ATL: TROPICAL STORM BILL (03L)

[CrazyC83]

... and the next flight has just taken off:

000
URNT15 KNHC 210150
AF300 0703A BILL HDOB 02 20090821
014100 1742N 06449W 0110 00000 0098 +255 +185 360000 000 999 999 23
014130 1742N 06449W 0109 00000 0098 +254 +185 027000 000 999 999 23
014200 1742N 06448W 0112 00000 0098 +248 +184 084001 005 999 999 23
014230 1742N 06447W 9925 00175 0117 +259 +185 171009 009 999 999 03
014300 1742N 06446W 9665 00410 0111 +237 +186 175009 010 999 999 03
014330 1743N 06444W 9260 00743 0079 +211 +186 171010 011 999 999 03
014400 1744N 06443W 8915 01069 0091 +190 +184 169013 014 999 999 03
014430 1746N 06442W 8541 01488 0128 +173 +173 170015 015 999 999 03
014500 1748N 06441W 8201 01834 0130 +153 +153 171013 014 999 999 03
014530 1749N 06440W 7846 02212 9990 +136 +999 164008 008 999 999 05
014600 1751N 06439W 7560 02520 9990 +119 +999 154007 009 999 999 05
014630 1753N 06440W 7268 02851 0125 +102 +054 129007 007 999 999 03
014700 1754N 06441W 7059 03089 0121 +086 +050 134007 007 999 999 03
014730 1756N 06442W 6966 03194 0117 +080 +050 140007 007 999 999 03
014800 1758N 06443W 6957 03203 0116 +076 +050 150008 009 999 999 03
014830 1759N 06445W 6959 03213 0125 +078 +050 155009 010 999 999 03
014900 1801N 06446W 6810 03394 0128 +066 +050 139010 011 999 999 03
014930 1803N 06447W 6609 03645 0120 +060 +050 147011 012 999 999 03
015000 1805N 06449W 6350 03977 0121 +043 +043 145009 010 999 999 03
015030 1806N 06450W 6155 04230 0122 +028 +028 134011 012 999 999 03
$$
;

You can go ahead and follow that one.

[HurricaneHunter914]

http://www.ssd.noaa.gov/goes/flt/t2/avn-l.jpg

West side of Bill is looking rather poor tonight.

[bdabye]

Bermuda checking in. That's a pretty scary sight to our SSE. There's a cat 4 knocking at our door. I sure hope the models are right and this thing stays off to our west. We're expecting some squally blustery weather tomorrow, just the ticket to break the heat. It's been flat glass calm and hot for a week. Swells from Bill have been picking up on the south shore all day, and were quite a sight before sunset rolling over the reef on an impressively high tide. In the morning they should be incredible, can't wait to see them
Suppose Bill intensifies to a cat 5. Is it possible that he creates his own steering environment that could jog it even closer to us?

[craptacular]

You can go ahead and follow that one.

I'll have to pass to another volunteer. I just wanted to point it out. It'll take them a while to get up to Bill anyway.

[cpdaman]

http://www.ssd.noaa.gov/goes/flt/t2/avn-l.jpg

West side of Bill is looking rather poor tonight.

yup NW and SW sides seems to be contracting with convection....best low level convergence is just on NE side of storm.......

in the last hour you can see this erosion of west side taking place more

possibly due to Sw shear pushing in a bit of dry air on the western flank

[RattleMan]

URNT15 KNHC 210200
AF300 0703A BILL HDOB 03 20090821
015100 1808N 06451W 5962 04459 0081 +018 +018 143010 011 999 999 03
015130 1810N 06452W 5757 04734 0064 +004 +004 152009 010 999 999 03
015200 1812N 06454W 5574 05005 0068 -010 -010 160008 009 999 999 03
015230 1813N 06455W 5405 05251 0259 -023 -023 181009 009 999 999 03
015300 1815N 06456W 5253 05486 0277 -035 -035 197006 008 999 999 03
015330 1817N 06457W 5100 05719 0292 -040 -040 191009 010 999 999 03
015400 1819N 06457W 4968 05905 0301 -049 -049 178008 008 999 999 03
015430 1821N 06458W 4842 06075 0139 -064 -064 169009 010 999 999 03
015500 1823N 06459W 4735 06305 0260 -074 -074 172012 013 999 999 03
015530 1824N 06459W 4634 06478 0348 -085 -085 171011 011 999 999 03
015600 1826N 06500W 4531 06648 0355 -097 -097 160007 008 999 999 03
015630 1828N 06501W 4423 06840 0374 -110 -180 172005 005 999 999 03
015700 1830N 06501W 4328 07012 0385 -116 -180 178006 007 999 999 03
015730 1832N 06502W 4250 07147 0395 -120 -180 178008 008 999 999 03
015800 1834N 06503W 4171 07291 0403 -132 -180 191007 007 999 999 03
015830 1836N 06503W 4090 07433 0411 -142 -180 193007 008 999 999 03
015900 1838N 06504W 4022 07563 0418 -147 -180 171008 009 999 999 03
015930 1840N 06505W 3950 07700 0424 -159 -180 176005 006 999 999 03
020000 1842N 06505W 3923 07745 0425 -164 -180 189004 004 999 999 03
020030 1844N 06506W 3925 07742 0423 -165 -180 192003 004 999 999 03
$$
;

I'll start the decoding once they descend to operational altitude.

000
URNT15 KNHC 210210
AF300 0703A BILL HDOB 04 20090821
020100 1846N 06507W 3923 07747 0424 -167 -180 211003 003 999 999 03
020130 1848N 06508W 3926 07738 0424 -167 -180 235004 005 999 999 03
020200 1851N 06508W 3928 07738 0425 -165 -180 253006 006 999 999 03
020230 1853N 06509W 3925 07749 0427 -165 -180 247006 006 999 999 03
020300 1853N 06509W 3925 07749 0427 -165 -180 247005 005 999 999 03
020330 1858N 06511W 3926 07740 0428 -165 -180 236006 006 006 000 03
020400 1900N 06512W 3928 07737 0428 -165 -180 234006 006 009 000 03
020430 1903N 06512W 3926 07746 0430 -165 -179 234006 006 004 000 03
020500 1905N 06513W 3927 07743 0429 -165 -177 231006 006 009 000 00
020530 1908N 06514W 3926 07744 0426 -165 -181 235005 005 006 000 00
020600 1910N 06515W 3926 07739 0425 -165 -185 231007 007 007 000 00
020630 1912N 06516W 3927 07736 0422 -165 -188 235006 007 008 000 03
020700 1915N 06517W 3926 07734 0421 -165 -191 241006 006 006 000 03
020730 1917N 06517W 3925 07740 0422 -165 -193 246006 006 006 000 03
020800 1920N 06518W 3926 07734 0421 -165 -195 249006 007 002 000 03
020830 1922N 06519W 3926 07735 0418 -165 -197 238008 008 004 000 03
020900 1924N 06520W 3926 07734 0418 -163 -199 231008 009 002 000 03
020930 1927N 06521W 3926 07732 0416 -165 -201 236008 009 000 000 00
021000 1929N 06522W 3926 07727 0415 -161 -202 237009 009 000 000 00
021030 1932N 06522W 3926 07733 0418 -161 -204 241009 009 002 000 03
$$
;

URNT15 KNHC 210220
AF300 0703A BILL HDOB 05 20090821
021100 1934N 06523W 3925 07737 0418 -160 -205 239008 008 004 000 03
021130 1936N 06524W 3926 07730 0415 -163 -206 244008 008 001 000 00
021200 1939N 06525W 3926 07728 0414 -162 -207 241008 008 004 000 03
021230 1941N 06526W 3926 07735 0416 -164 -209 247008 008 005 000 03
021300 1943N 06527W 3926 07732 0416 -164 -210 256008 008 003 000 03
021330 1946N 06527W 3926 07735 0418 -165 -210 263008 008 003 000 03
021400 1948N 06528W 3926 07736 0419 -162 -212 271008 008 004 000 00
021430 1951N 06529W 3926 07735 0420 -161 -213 280008 008 002 000 00
021500 1953N 06530W 3926 07736 0420 -160 -214 286008 008 003 000 00
021530 1955N 06531W 3928 07735 0423 -160 -216 276007 007 003 000 03
021600 1958N 06531W 3926 07737 0420 -160 -220 265007 008 002 000 03
021630 2000N 06532W 3926 07732 0419 -160 -222 262008 008 002 000 03
021700 2002N 06533W 3926 07733 0420 -160 -223 261007 008 002 000 03
021730 2005N 06534W 3926 07734 0419 -160 -224 262007 008 002 000 03
021800 2007N 06535W 3926 07738 0421 -160 -224 268008 008 002 000 00
021830 2009N 06536W 3926 07740 0421 -160 -226 267008 009 004 000 03
021900 2012N 06536W 3926 07736 0421 -160 -226 269008 008 002 000 03
021930 2014N 06537W 3926 07738 0422 -160 -227 272009 009 004 000 03
022000 2016N 06538W 3926 07736 0422 -160 -227 271009 009 003 000 03
022030 2019N 06539W 3926 07739 0422 -160 -228 261009 009 001 000 00
$$
;

000
URNT15 KNHC 210230
AF300 0703A BILL HDOB 06 20090821
022100 2021N 06540W 3926 07734 0423 -161 -228 258009 010 002 000 00
022130 2024N 06541W 3926 07734 0422 -165 -228 258008 008 004 000 00
022200 2026N 06541W 3926 07742 0422 -162 -228 258008 008 001 000 00
022230 2028N 06542W 3926 07738 0421 -161 -228 261008 008 004 000 03
022300 2031N 06543W 3926 07736 0421 -160 -225 262008 009 002 000 03
022330 2033N 06544W 3926 07736 0422 -161 -223 260008 008 004 000 00
022400 2035N 06545W 3927 07737 0422 -165 -221 263008 008 004 000 03
022430 2038N 06546W 3926 07744 0422 -165 -220 265008 008 002 000 03
022500 2040N 06546W 3926 07737 0422 -166 -220 263008 008 002 000 00
022530 2043N 06547W 3927 07738 0421 -167 -219 267008 009 004 000 00
022600 2045N 06548W 3925 07742 0421 -165 -218 277009 009 002 000 00
022630 2047N 06549W 3929 07730 0421 -164 -217 279009 009 002 000 03
022700 2050N 06550W 3921 07749 0422 -163 -218 279009 009 005 000 03
022730 2052N 06551W 3929 07733 0420 -160 -219 277009 009 001 000 00
022800 2054N 06551W 3923 07741 0420 -162 -219 279009 009 001 000 00
022830 2057N 06552W 3923 07742 0420 -163 -220 286010 010 999 999 03
022900 2059N 06553W 3926 07734 0418 -164 -220 286010 010 006 000 03
022930 2101N 06554W 3926 07734 0418 -165 -220 290010 010 006 000 03
023000 2104N 06555W 3928 07729 0418 -166 -220 303011 013 004 000 03
023030 2106N 06555W 3927 07733 0417 -170 -220 310013 013 005 000 03
$$
;

000
URNT15 KNHC 210240
AF300 0703A BILL HDOB 07 20090821
023100 2108N 06556W 3923 07739 0418 -165 -219 302011 011 004 000 03
023130 2110N 06557W 3930 07727 0417 -166 -219 303012 013 004 000 03
023200 2113N 06558W 3921 07743 0418 -163 -218 294011 011 005 000 03
023230 2115N 06559W 3929 07731 0418 -161 -220 297011 012 004 000 00
023300 2117N 06600W 3925 07735 0418 -164 -222 300012 013 004 000 03
023330 2120N 06600W 3926 07735 0419 -165 -224 299012 013 006 000 00
023400 2122N 06601W 3926 07732 0418 -162 -224 296012 013 006 000 00
023430 2124N 06602W 3926 07730 0418 -165 -223 298013 014 006 000 00
023500 2127N 06603W 3926 07731 0419 -165 -223 301014 014 001 000 03
023530 2129N 06603W 3926 07735 0418 -165 -222 296013 013 003 000 03
023600 2132N 06603W 3925 07734 0417 -163 -222 290012 012 005 000 00
023630 2134N 06603W 3929 07725 0418 -160 -221 293012 013 008 000 00
023700 2136N 06603W 3926 07739 0419 -165 -222 300014 014 007 000 00
023730 2139N 06603W 3926 07728 0418 -165 -224 299014 014 011 000 00
023800 2141N 06603W 3925 07736 0418 -167 -224 295014 014 010 000 00
023830 2144N 06603W 3927 07725 0417 -166 -223 291015 016 008 000 00
023900 2146N 06603W 3925 07729 0417 -167 -222 291016 016 009 000 00
023930 2149N 06602W 3930 07725 0416 -168 -222 290016 017 010 000 00
024000 2151N 06602W 3923 07739 0416 -170 -224 297018 019 011 000 03
024030 2154N 06602W 3926 07728 0415 -170 -224 298018 019 009 000 03
$$
;

000
URNT15 KNHC 210250
AF300 0703A BILL HDOB 08 20090821
024100 2156N 06602W 3923 07732 0414 -170 -224 294018 018 014 000 03
024130 2158N 06602W 3929 07723 0412 -170 -226 291018 018 011 000 03
024200 2201N 06602W 3925 07730 0412 -169 -229 289018 019 014 000 00
024230 2203N 06602W 3927 07725 0412 -170 -232 292019 020 015 000 00
024300 2206N 06602W 3921 07735 0411 -169 -235 285019 019 017 000 00
024330 2208N 06602W 3930 07721 0411 -166 -234 287019 020 016 000 00
024400 2211N 06602W 3926 07730 0412 -166 -233 286019 019 014 000 00
024430 2213N 06602W 3926 07723 0411 -165 -233 289020 020 019 000 03
024500 2216N 06602W 3926 07730 0411 -165 -232 286021 021 017 000 03
024530 2218N 06601W 3923 07730 0409 -165 -233 288021 021 015 000 03
024600 2221N 06601W 3930 07720 0409 -163 -234 294022 023 016 000 00
024630 2223N 06601W 3927 07720 0408 -160 -235 294022 023 016 000 00
024700 2225N 06601W 3922 07734 0407 -156 -234 293022 022 013 000 03
024730 2228N 06601W 3930 07714 0407 -155 -234 291022 023 013 000 00
024800 2230N 06601W 3923 07723 0407 -156 -236 292022 022 018 000 00
024830 2233N 06601W 3926 07721 0407 -155 -236 294022 023 018 000 03
024900 2235N 06601W 3926 07716 0406 -155 -235 293021 022 019 000 03
024930 2238N 06601W 3927 07719 0407 -155 -232 297023 023 019 000 03
025000 2240N 06601W 3926 07726 0406 -155 -230 298024 024 018 000 00
025030 2242N 06601W 3927 07720 0405 -155 -230 300024 025 020 000 00
$$
;

Descending:

000
URNT15 KNHC 210300
AF300 0703A BILL HDOB 09 20090821
025100 2245N 06601W 3925 07727 0405 -155 -231 302025 025 022 000 03
025130 2247N 06600W 3926 07720 0404 -154 -232 300025 025 022 000 03
025200 2250N 06600W 3926 07717 0404 -150 -232 296025 025 021 000 03
025230 2252N 06600W 3926 07724 0404 -150 -232 299025 026 021 000 00
025300 2254N 06600W 3926 07720 0403 -150 -232 300026 026 024 000 03
025330 2257N 06600W 3925 07717 0401 -150 -232 296026 026 025 000 00
025400 2259N 06600W 3929 07711 0400 -154 -232 300026 027 026 000 00
025430 2302N 06600W 3994 07589 0392 -146 -230 303025 026 025 000 00
025500 2304N 06559W 4148 07299 0372 -129 -228 301029 032 025 000 00
025530 2306N 06559W 4292 07039 0354 -112 -227 304033 034 027 000 00
025600 2309N 06558W 4434 06780 0334 -103 -229 301035 035 028 000 03
025630 2311N 06558W 4586 06517 0311 -084 -235 305036 036 026 000 00
025700 2313N 06557W 4732 06272 0298 -062 -240 307034 035 028 000 00
025730 2315N 06557W 4877 06043 0286 -053 -237 303032 032 030 000 00
025800 2317N 06557W 5029 05796 0267 -043 -224 308036 038 031 002 00
025830 2319N 06556W 5187 05552 0248 -024 -211 307038 039 034 001 00
025900 2321N 06556W 5339 05316 0231 -001 -200 312040 041 033 000 00
025930 2323N 06555W 5500 05070 9985 +012 -188 329041 042 030 002 00
030000 2325N 06555W 5669 04823 0019 +007 -175 331034 037 027 002 00
030030 2327N 06555W 5820 04597 0007 +019 -163 335032 033 027 000 00
$$
;

Now near operational altitude:

000
URNT15 KNHC 210310
AF300 0703A BILL HDOB 10 20090821
030100 2329N 06554W 5979 04377 0027 +025 -152 342032 034 027 000 00
030130 2331N 06554W 6143 04186 0060 +031 -140 337034 035 026 001 03
030200 2333N 06554W 6324 03947 0074 +036 -130 327033 035 029 001 00
030230 2334N 06555W 6481 03748 0061 +055 -119 331035 039 031 001 00
030300 2336N 06555W 6659 03517 0058 +068 -108 335040 040 033 002 00
030330 2338N 06555W 6845 03283 0072 +067 -095 334041 043 034 001 00
030400 2339N 06556W 6944 03162 0091 +055 -084 328042 042 034 006 00
030430 2341N 06556W 6971 03127 0076 +067 -075 342043 046 035 008 00
030500 2343N 06556W 6964 03143 0055 +084 -070 343047 049 032 002 00
030530 2344N 06557W 6964 03135 0067 +072 -064 338042 046 032 005 00
030600 2346N 06557W 6976 03124 0073 +067 -056 345047 048 033 006 00
030630 2347N 06557W 6966 03134 0056 +079 -053 344049 050 034 000 00
030700 2349N 06558W 6965 03135 0063 +073 -050 343050 051 033 001 00
030730 2350N 06558W 6966 03135 0061 +073 -043 347052 053 037 002 00
030800 2352N 06558W 6966 03129 0055 +077 -038 346052 053 038 002 00
030830 2352N 06558W 6966 03129 0049 +082 -033 348054 055 038 002 00
030900 2355N 06559W 6980 03113 0050 +081 -024 349055 057 036 003 00
030930 2356N 06559W 6960 03137 0053 +077 -016 351057 057 037 001 00
031000 2357N 06559W 6967 03127 0047 +079 -010 352057 057 035 003 00
031030 2359N 06600W 6970 03125 0053 +076 -005 353058 059 037 004 00
$$
;

[btangy]

Comparing the 00Z NAM analysis (which I assume has ingested the dropsonde data from the synoptic surveillance missions), there's not all that much difference between the analysis and the 12Z 12 hour forecast. It looks like the planes sampled the region between Bill and the SE US and also sampled the outer structure of Bill. I would have liked to see a few sondes E of Bermuda to asses the strength of the ridge to the NE, but perhaps that was too far out for the planes or they had sensitivity info beforehand.

00Z NAM still looks to be overemphasizing the low just NE of the Bahamas in the short term. Bill's massive outflow will probably just shove it out of the way.

Midwest trough -- Similar position and continuing the trend of lower heights on the SW side. Is a bit less progressive, but not enough to raise any flags to change the track reasoning for Bill.

EDIT: I spoke a bit too soon. By 60 hours, the NAM is about as close as I've seen it to cutting off the 500mb low and has the low further W over Michigan. This backs the 500mb flow a bit more southerly (vs SW-ly). Will have to wait to see the 00Z global models to see if they also are indicating this shift and whether that pushes Bill's track toward the W. Think all that convection in the Midwest is playing havoc with this trough forecast.

[MGC]

Bill seems to be loosing his west side. Still a good looking hurricane.....MGC

[cycloneye]

Bermuda checking in. That's a pretty scary sight to our SSE. There's a cat 4 knocking at our door. I sure hope the models are right and this thing stays off to our west. We're expecting some squally blustery weather tomorrow, just the ticket to break the heat. It's been flat glass calm and hot for a week. Swells from Bill have been picking up on the south shore all day, and were quite a sight before sunset rolling over the reef on an impressively high tide. In the morning they should be incredible, can't wait to see them
Suppose Bill intensifies to a cat 5. Is it possible that he creates his own steering environment that could jog it even closer to us?

Hi there.Is there a radar that we can see what is going on? Stay safe over there.

[vbhoutex]

Bermuda checking in. That's a pretty scary sight to our SSE. There's a cat 4 knocking at our door. I sure hope the models are right and this thing stays off to our west. We're expecting some squally blustery weather tomorrow, just the ticket to break the heat. It's been flat glass calm and hot for a week. Swells from Bill have been picking up on the south shore all day, and were quite a sight before sunset rolling over the reef on an impressively high tide. In the morning they should be incredible, can't wait to see them
Suppose Bill intensifies to a cat 5. Is it possible that he creates his own steering environment that could jog it even closer to us?

It is possible as CAT5 storms do tend to sometimes "create their own environment" but I don't think Bill is going to make CAT5 plus the steering he is being moved by is pretty strong in and of itself(or that is my impression). Anyone with better knowledge feel free to correct me.

[bdabye]

Bda radar
http://www.weather.bm/radarLarge.asp
Extended radar etc:
http://199.172.239.3/gemamet/index.jsp

Outer fringe tstorms showing up now

[Brent]

BULLETIN
HURRICANE BILL ADVISORY NUMBER 23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
1100 PM AST THU AUG 20 2009

...POWERFUL HURRICANE BILL REMAINS ON TRACK...

A TROPICAL STORM WARNING AND A HURRICANE WATCH ARE IN EFFECT FOR
BERMUDA. A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM
CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 24
HOURS. A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 36 HOURS.

INTERESTS ALONG THE COAST OF NEW ENGLAND AND IN THE CANADIAN
MARITIMES SHOULD MONITOR THE PROGRESS OF BILL.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE OF THE UNITED
STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE. FOR STORM INFORMATION SPECIFIC TO YOUR
AREA IN THE UNITED STATES...INCLUDING POSSIBLE INLAND WATCHES AND
WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL
WEATHER SERVICE FORECAST OFFICE.

AT 1100 PM AST...0300 UTC...THE CENTER OF HURRICANE BILL WAS LOCATED
NEAR LATITUDE 24.9 NORTH...LONGITUDE 64.3 WEST OR ABOUT 510 MILES...
825 KM...SOUTH OF BERMUDA AND ABOUT 975 MILES...1570 KM...SOUTHEAST
OF CAPE HATTERAS NORTH CAROLINA.

BILL IS MOVING TOWARD THE NORTHWEST NEAR 18 MPH...30 KM/HR. THIS
MOTION SHOULD CONTINUE THROUGH TONIGHT WITH A GRADUAL TURN TO THE
NORTH-NORTHWEST ON FRIDAY...FOLLOWED BY A TURN TOWARD THE NORTH ON
SATURDAY. ON THE FORECAST TRACK...THE CORE OF THE HURRICANE IS
EXPECTED TO PASS BETWEEN BERMUDA AND THE EAST COAST OF THE UNITED
STATES ON SATURDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 125 MPH...205 KM/HR...WITH HIGHER
GUSTS. BILL IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. SOME FLUCTUATIONS IN INTENSITY ARE LIKELY DURING THE NEXT 12
TO 24 HOURS...AND BILL COULD REGAIN CATEGORY FOUR STRENGTH ON
FRIDAY. GRADUAL WEAKENING IS EXPECTED TO BEGIN ON SATURDAY.

BILL IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND
OUTWARD UP TO 115 MILES...185 KM...FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 260 MILES...415 KM.

THE LATEST MINIMUM CENTRAL PRESSURE ESTIMATE BY A NOAA HURRICANE
HUNTER PLANE WAS 943 MB...27.85 INCHES.

BILL IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF 2 TO 4
INCHES OVER BERMUDA...WITH POSSIBLY SOME AMOUNTS OF 6 INCHES.

SIGNIFICANT COASTAL FLOODING IS EXPECTED ALONG PORTIONS OF THE
BERMUDA COASTLINE OVER THE NEXT DAY OR TWO DUE TO LARGE AND
DANGEROUS BREAKING WAVES GENERATED BY BILL.

LARGE SWELLS GENERATED BY THIS HURRICANE ARE AFFECTING PUERTO
RICO...HISPANIOLA...THE BAHAMAS...AND BERMUDA...AND SHOULD BEGIN
AFFECTING MOST OF THE U.S. EAST COAST AND THE ATLANTIC MARITIMES OF
CANADA DURING THE NEXT DAY OR TWO. THESE SWELLS WILL LIKELY CAUSE
EXTREMELY DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS. PLEASE
CONSULT STATEMENTS ISSUED BY YOUR LOCAL WEATHER OFFICE FOR MORE
DETAILS.

...SUMMARY OF 1100 PM AST INFORMATION...
LOCATION...24.9N 64.3W
MAXIMUM SUSTAINED WINDS...125 MPH
PRESENT MOVEMENT...NORTHWEST OR 310 DEGREES AT 18 MPH
MINIMUM CENTRAL PRESSURE...943 MB

AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE
CENTER AT 200 AM AST FOLLOWED BY THE NEXT COMPLETE ADVISORY AT 500
AM AST.

$$
FORECASTER BROWN/PASCH

HURRICANE BILL FORECAST/ADVISORY NUMBER 23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
0300 UTC FRI AUG 21 2009

A TROPICAL STORM WARNING AND A HURRICANE WATCH ARE IN EFFECT FOR
BERMUDA. A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM
CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 24
HOURS. A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 36 HOURS.

INTERESTS ALONG THE COAST OF NEW ENGLAND AND IN THE CANADIAN
MARITIMES SHOULD MONITOR THE PROGRESS OF BILL.

HURRICANE CENTER LOCATED NEAR 24.9N 64.3W AT 21/0300Z
POSITION ACCURATE WITHIN 10 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 16 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 943 MB
EYE DIAMETER 30 NM
MAX SUSTAINED WINDS 110 KT WITH GUSTS TO 135 KT.
64 KT.......100NE 45SE 30SW 90NW.
50 KT.......130NE 105SE 60SW 105NW.
34 KT.......225NE 200SE 120SW 200NW.
12 FT SEAS..420NE 360SE 300SW 300NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 24.9N 64.3W AT 21/0300Z
AT 21/0000Z CENTER WAS LOCATED NEAR 24.3N 63.8W

FORECAST VALID 21/1200Z 26.9N 66.1W
MAX WIND 115 KT...GUSTS 140 KT.
64 KT...100NE 45SE 30SW 90NW.
50 KT...130NE 105SE 60SW 105NW.
34 KT...225NE 200SE 120SW 200NW.

FORECAST VALID 22/0000Z 29.6N 67.9W
MAX WIND 115 KT...GUSTS 140 KT.
64 KT...100NE 45SE 30SW 90NW.
50 KT...130NE 105SE 60SW 105NW.
34 KT...225NE 200SE 120SW 200NW.

FORECAST VALID 22/1200Z 32.7N 68.9W
MAX WIND 110 KT...GUSTS 135 KT.
64 KT...100NE 45SE 30SW 90NW.
50 KT...130NE 130SE 60SW 105NW.
34 KT...225NE 225SE 120SW 200NW.

FORECAST VALID 23/0000Z 36.4N 68.6W
MAX WIND 100 KT...GUSTS 120 KT.
50 KT...130NE 130SE 90SW 105NW.
34 KT...225NE 225SE 150SW 180NW.

FORECAST VALID 24/0000Z 44.3N 62.0W
MAX WIND 80 KT...GUSTS 100 KT.
50 KT...130NE 130SE 100SW 100NW.
34 KT...225NE 250SE 200SW 180NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 225 NM
ON DAY 4 AND 300 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 25/0000Z 50.5N 43.0W...EXTRATROPICAL
MAX WIND 55 KT...GUSTS 65 KT.

OUTLOOK VALID 26/0000Z 55.0N 20.0W...EXTRATROPICAL
MAX WIND 50 KT...GUSTS 60 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 24.9N 64.3W

NEXT ADVISORY AT 21/0900Z

$$
FORECASTER BROWN/PASCH

HURRICANE BILL DISCUSSION NUMBER 23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
1100 PM AST THU AUG 20 2009

THE SATELLITE PRESENTATION OF BILL HAS CHANGED LITTLE THIS EVENING.
THE LARGE EYE REMAINS VERY WELL-DEFINED...HOWEVER THE CLOUD TOPS
SURROUNDING THE EYE HAVE WARMED SLIGHTLY DURING THE PAST COUPLE OF
HOURS. THE NOAA RECONNAISSANCE AIRCRAFT THAT HAS BEEN SAMPLING THE
CORE OF THE HURRICANE THIS EVENING REPORTED A PEAK BELIEVABLE
FLIGHT-LEVEL WIND OF 127 KT. ALTHOUGH HIGHER WIND SPEEDS WERE
REPORTED...THE METEOROLOGISTS ON THE AIRCRAFT DID NOT CONSIDER
THOSE HIGHER WINDS TO BE VALID. DVORAK DATA T-NUMBERS HAVE
DECREASED SLIGHTLY. BASED ON ALL OF THE DATA...THE INITIAL
INTENSITY IS HELD AT 110 KT. ENVIRONMENTAL FACTORS ARE EXPECTED TO
REMAIN CONDUCIVE FOR SOME RESTRENGTHENING DURING THE NEXT 24 HOURS
OR SO. AFTERWARDS...SOME COOLING OF THE SSTS WILL LIKELY INDUCE A
SLOW WEAKENING TREND. VERTICAL WIND SHEAR IS PREDICTED BY THE
SHIPS MODEL TO REMAIN LIGHT UNTIL THE HURRICANE NEARS THE CANADIAN
MARITIMES IN ABOUT 72 HOURS. HOWEVER...SSTS ALONG THE FORECAST
TRACK WILL BEGIN TO COOL MORE RAPIDLY AROUND THAT TIME...AND SHEAR
IS FORECAST TO INCREASE SIGNIFICANTLY VERY SOON THEREAFTER. THE
OFFICIAL WIND SPEED FORECAST IS GENERALLY BETWEEN THE SHIPS AND
LGEM GUIDANCE

BILL CONTINUES TO MOVE NORTHWESTWARD OR 310/16 KT. THERE IS NOT MUCH
NEW TO SAY ABOUT THE TRACK FORECAST. BILL IS EXPECTED TO TURN
NORTHWARD AHEAD OF A STRONG MID-LATITUDE TROUGH THAT WILL MOVE INTO
THE EASTERN U.S. DURING THE NEXT COUPLE OF DAYS...AND RECURVE AHEAD
OF THAT TROUGH THEREAFTER. THE NEW TRACK FORECAST IS VIRTUALLY
UNCHANGED FROM THE PREVIOUS ADVISORY AND IS ONCE AGAIN IN EXCELLENT
AGREEMENT WITH THE TIGHTLY CLUSTERED MODEL GUIDANCE.

LARGE SWELLS GENERATED BY THIS HURRICANE ARE AFFECTING...OR WILL
AFFECT...A LARGE PORTION OF THE WESTERN NORTH ATLANTIC COASTAL AREA
DURING THE NEXT FEW DAYS. THESE SWELLS WILL LIKELY CAUSE EXTREMELY
DANGEROUS SURF AND LIFE-THREATENING RIP CURRENTS. PLEASE CONSULT
STATEMENTS ISSUED BY YOUR LOCAL WEATHER OFFICE FOR MORE DETAILS.

DATA FROM A TWO-AIRCRAFT SYNOPTIC SURVEILLANCE MISSION CONDUCTED BY
NOAA AND U.S. AIR FORCE RESERVE AIRCRAFT THIS EVENING SHOULD BE
ASSIMILATED INTO THE INITIALIZATION OF THE 0000 UTC MODEL RUNS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 21/0300Z 24.9N 64.3W 110 KT
12HR VT 21/1200Z 26.9N 66.1W 115 KT
24HR VT 22/0000Z 29.6N 67.9W 115 KT
36HR VT 22/1200Z 32.7N 68.9W 110 KT
48HR VT 23/0000Z 36.4N 68.6W 100 KT
72HR VT 24/0000Z 44.3N 62.0W 80 KT
96HR VT 25/0000Z 50.5N 43.0W 55 KT...EXTRATROPICAL
120HR VT 26/0000Z 55.0N 20.0W 50 KT...EXTRATROPICAL

$$
FORECASTER BROWN/PASCH

[Andrew92]

I've been watching this storm really closely, hoping it doesn't hit land, and WOW is this an amazing storm to track! Intense, beautiful, yet so far hasn't hit land.

Just wondering, what are the chances this first goes in between Bermuda and the East Coast, then recurves sharply enough that it manages to miss Nova Scotia and Newfoundland? I know they're probably not good, but that would make a storm like Bill almost a model storm to track, just to see the beautiful power of a hurricane but not over land.

-Andrew92

[Brent]

[CrazyC83]

They decided to omit the 148 and 159 kt reports, suggesting they are invalid. I didn't see anything in the data suggesting the flight-level winds were flagged there...

[JonathanBelles]

I probably would have put it at 130-135mph with the recon reports from earlier. Recon probably supported 140mph. The satellite appearance has come down since earlier, as the NHC has said, but I dont think that the clouds have warmed enough to bring it back to 125mph.

[RL3AO]

They decided to omit the 148 and 159 kt reports, suggesting they are invalid. I didn't see anything in the data suggesting the flight-level winds were flagged there...

I'm guessing the crew knows what 159kt gusts feel like on that plane and the turbulence didn't indicate 159kt winds.

[Derek Ortt]

you get different turbulence in different wind speeds

I was knocked on my rear during a rainband of Rita. Meanwhile, the eyewall was quite smooth

[massweathernet]

Via Twitter:

[superfly]

The entire western side is getting wiped out.