Updated Forecast and Graphic

[PhillyWX]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

http://philadelphiaweather.blogspot.com/2005/10/afternoon-update-with-event.html

[aerojad]

aren't Tammy's leftovers moving south into the GOM and not up the east coast?

[WindRunner]

aren't Tammy's leftovers moving south into the GOM and not up the east coast?

No, we're definately feeling the rain up here in Northern Virginia. Expecting 3-5 inches the next two days compared to our half inch the past month and a half.

[hurricanedude]

sorry wild runner, your rain is not from TAMMY!!!!!!!!!!
Some scattered showers will occur over the eastern Gulf Coast
region in association with the remnants of Tammy. Heavier rains
are likely over the southern mid Atlantic states... but these
rains are not associated with Tammy... but are the result of deep
moisture coming into the region ahead of an approaching cold
front.

[hurricanedude]

and yes the remnants are gulf bound

.The remnants of Tammy moving south towards the Gulf of
Mexico...
All flood watches along the path of Tammy have been discontinued.

[PhillyWX]

aren't Tammy's leftovers moving south into the GOM and not up the east coast?

The LLC is, but the moisture is moving up the coast. Remember that Tammy's center was only a tiny part of the entire system. Most of the moisture from Tammy was drug north and is now being sucked up ahead of the front.

That's more important than what a LLC that's decoupled from its moisture source is going to do over Alabama and the FL panhandle.

[PhillyWX]

sorry wild runner, your rain is not from TAMMY!!!!!!!!!!
Some scattered showers will occur over the eastern Gulf Coast
region in association with the remnants of Tammy. Heavier rains
are likely over the southern mid Atlantic states... but these
rains are not associated with Tammy... but are the result of deep
moisture coming into the region ahead of an approaching cold
front.

Source please?

[PhillyWX]

For what it's worth...

Mount Holly NWS AFD:

SHORT TERM (TONIGHT THROUGH SATURDAY)...
SCATTERED CONVECTION HAS DEVELOPED THIS AFTERNOON ACROSS SOUTHERN
NEW JERSEY AND DELAWARE AS THE MOIST AIR MASS IN PLACE, SOME WEAK
HEATING AND WEAK ISENTROPIC LIFT HAVE ALL COME TOGETHER AT THE SAME
TIME. I WOULD EXPECT THAT THE COVERAGE OF THE SHOWERS WOULD DIMINISH
OVERNIGHT...BUT I WILL STILL LEAVE THE CHC POPS GOING FOR NOW. THERE
WILL PROBABLY BE SOME FOG OVERNIGHT...BUT THE EXTENT AND MAGNITUDE
OF IT WONT BE ENOUGH TO PUT IT IN THE GRIDS ATTM.

THE "MAIN EVENT" BEGINS ON FRIDAY. THE SLOWLY APPROACHING COLD FRONT
AND THE REMNANTS OF TAMMY WILL MOVE ACROSS OUR REGION FRIDAY THROUGH
SATURDAY. THE SYSTEM IS EXPECTED TO PRODUCE A WIDESPREAD AND
SUBSTANTIAL RAINFALL FOR THE REGION. THE HYDROLOGY SECTION BELOW
WILL DESCRIBE THE EFFECT THAT THE RAINS WILL HAVE ON THE AREA. THE
RAINS WHICH WILL BE HEAVY AT TIMES WILL SWEEP IN FROM SW TO NE
BEGINNING LATE MORNING OVER DELMARVA. THUNDER CHCS LOOK LOW ENOUGH
TO KEEP OUT OF THE GRIDS FOR NOW.

THE STEADY AND HEAVY RAINS WILL CONTINUE FRIDAY NIGHT AND THEN
SLOWLY TAPER OFF EARLY SATURDAY. THE SFC FRONT WILL MOVE ACROSS THE
REGION SATURDAY AS THE SFC LOW(S) PULL AWAY TOWARDS NEW ENGLAND.
MODELS INCONSISTENT AT LATER PERIODS REGARDING FRONTAL MOVEMENT AND
QPF AMOUNTS...SO JUST USED LIKELY TERMINOLOGY FOR NOW. MUCH OF THE
HEAVIEST QPF WILL BE DONE BY 18Z SAT IN MOST AREAS. SPOTTY SHOWERS
WILL PREVAIL SATURDAY AFTERNOON.

Binghamton NWS AFD:

SLOW-MOVING COLD FRONT WILL TAP PLENTY OF TROPICAL MOISTURE...
INCLUDING THE REMAINS OF TAMMY... TO PRODUCE HEAVY RAIN STARTING
FRIDAY. EXPECT SHOWERS TO STREAK NORTH ALONG THE FRONT LATE
TONIGHT... REACHING WEST CENTRAL NY INCLUDING THE FINGER LAKES AREA
AFTER MIDNIGHT... THEN SPREADING SLOWLY EAST ON FRIDAY. THREAT FOR
HEAVY RAINS INCREASE LATER FRIDAY AS POTENT RRQUAD UPPER DYNAMICS
SET UP... ALONG WITH A STRONG FRONTAL CIRCULATION WHICH WILL INDUCE
A 50 KT PLUS LOW-LEVEL SSERLY JET. PLENTY OF TROPICAL MOISTURE...
WITH PWAT VALUES EXCEEDING 1.5 INCHES WILL BECOME ENTRAINED INTO
THIS CIRCULATION BY LATE IN THE DAY. -

If the NWS is saying it's the remnants of Tammy, then it is. It doesn't have to be the LLC -- that's like saying Hurricane Otis did not impact the cold front when it dropped six inches of rain on the Upper Midwest. The front sucked up mid and high level moisture from Otis as it spun down off of the Baja.

[wxwatcher91]

here is the long-term section and the hydrology section from the Taunton, MA NWS forecast discussion looks like big rains a comin!!!

000
FXUS61 KBOX 062114 AAA
AFDBOX

AREA FORECAST DISCUSSION..FINAL DAY SHIFT
NATIONAL WEATHER SERVICE TAUNTON MA
514 PM EDT THU OCT 6 2005

.LONG TERM (SATURDAY THROUGH THURSDAY)...
..HEAVY RAIN EXPECTED SATURDAY AND SATURDAY NIGHT FOLLOWED BY COOL
AND DREARY WEATHER THROUGH MUCH OF NEXT WEEK...

THE MODELS CONTINUE TO SLOW THE PROGRESSION OF THE COLD FRONT DOWN
WITH THE STRONG UPPER LEVEL RIDGE ANCHORED OVER THE ATLANTIC.
GFS/ECMWF/NOGAPS/CANADIAN HAVE COME INTO EXCELLENT AGREEMENT IN
SHOWING HEAVY RAIN DEVELOPING ACROSS THE INERIOR SO CONFIDENCE IS
HIGHER THAN THE PAST FEW DAYS BUT CERTAINLY NOT SET IN STONE. ON
SATURDAY...WILL BE RUNNING 100 POPS TO THE NORTHWEST OF THE I-95
CORRIDOR. THESE MEDIUM RANGE MODELS ALL SHOW TREMENDOUS LIFT
DEVELOPING ALONG THE BOUNDARY PRODUCED BY STRONG SOUTHWEST FLOW
ALOFT...TRANSPORTING COPIOUS AMOUNTS OF TROPICAL MOISTURE NORTHWARD.
BASED ON THE SLOW MOVEMENT OF THE FRONT...EXPECT HEAVY RAINFALL TO
BE LOCATED TO THE NORTHWEST OF THE BOSTON TO PROVIDENCE CORRIDOR
THROUGH LATE AFTERNOON WHERE THE MAIN FOCUS IS SETUP. HOWEVER...A 55
TO 65 KNOT LOW LEVEL JET TO THE SOUTHEAST OF THIS REGION WILL RESULT
IN ENOUGH OMEGA TO PRODUCE HEAVY RAIN SHOWERS SO WILL EVEN BE GOING
WITH LIKELY TO CATEGORICAL POPS FOR THE CAPE AND ISLANDS.

SATURDAY EVENING EXPECT THE HEAVY RAIN TO SHIFT SOUTHEAST TOWARDS
THE COASTAL PLAIN BUT AMOUNTS ARE NOT EXPECTED TO BE AS HIGH AS IN
THE INTERIOR. WILL HAVE 100 POPS TO REFLECT THIS AS WELL. QPF IS
ALWAYS TRICKY TO FORECAST THIS FAR OUT BUT WITH SUCH STRONG LIFT AND
LOW LEVEL MOISTURE AVAILABLE EXPECT AMOUNTS TO BE HIGH. BASED ON
MODEL CONSENSUS EXPECTING WIDESPREAD RAINFALL AMOUNTS OF BETWEEN 2
AND 4 INCHES BY DAYBREAK SUNDAY TO THE NORTHWEST OF I-95 WITH A
GENERAL 1 TO 2 INCHES SOUTHEAST OF I-95. AMOUNTS WILL VARY MORE
ACROSS AREAS SOUTHEAST OF I-95 WITH TROPICAL LIKE SCATTERED RAIN
SHOWERS THAT MAY PRODUCE BRIEF TORRENTIAL RAIN.

AS FOR FLOODING...THE RIVER FORECAST CENTER RAN A CONTINGENCY MODEL
BASED ON 2 TO 4 INCHES OF RAIN ACROSS THE INTERIOR. IF THIS
OCCURS...MOST OF THE MAINSTEM RIVERS SHOULD BE OKAY OR AT THE WORST
SEE SOME MINOR FLOODING WITH OUR RECENT DRY WEATHER. HOWEVER...WE
WILL HAVE TO WATCH FOR URBAN TYPE OF FLOODING AS WELL AS THE SMALLER
CREEKS AND STREAMS WHICH ARE USUALLY QUICK RESPONDERS.

AS FOR TEMPERATURES...EXPECTED HIGHS SATURDAY IN THE UPPER 60S AND
LOWER 70S WITH THE FRONT STILL TO OUR WEST. FRONT MAY EVEN MOVE A
BIT SLOWER THAN PROGGED BASED ON THE LATEST GFS MODELS.

IT ALSO WILL BECOME WINDY WITH 65 KNOTS OF WIND AT 850 MB
PROGGED. WE MAY EVENTUALLY NEED A WIND ADVISORY FOR PORTION OF THE
AREA PARTICULARLY THE SOUTH COAST CAPE AND ISLANDS.

THE FORECAST BECOMES VERY UNCERTAIN IN THE SUNDAY THROUGH WEDNESDAY
TIME FRAME. DESPITE THE COLD FRONT OFF SHORE WE REMAIN IN SOUTHWEST
FLOW ALOFT. THIS OVER RUNNING WILL RESULT IN A RATHER CLOUDY AND
COOL NORTHEAST FLOW THROUGH THE TIME FRAME. THE QUESTION IS HOW MUCH
RAIN WE WILL RECEIVE. BASICALLY...THERE IS A LOT OF UNCERTAINTY IN
THIS REGARDS BUT THE ONE THING IT LOOKS LIKE IS A RATHER COOL AND
CLOUDY PERIOD WITH PERIODS OF RAIN. NORTHEAST WINDS AT THE SURFACE
WITH SOUTH WINDS SUPPORTING IN OMEGA JUST OFF THE GROUND.

THE LATEST 12Z GFS/12Z ECMWF INDICATED ANOTHER ROUND OF POTENTIAL
HEAVY RAIN...BUT ALL THE MEDIUM RANGE MODELS ARE NOT ON BOARD.
THEREFORE...WILL CARRY CHANCE POPS RIGHT THROUGH THE PERIOD. IF WE
DO END UP GETTING ANOTHER ROUND OF HEAVY RAIN...MAINSTEM RIVER
FLOODING WOULD BE A CONCERN. USUALLY WE NEED TWO CONSECUTIVE HEAVY
RAIN EVENTS TO RESULT IN SIGNIFICANT MAINSTEM RIVER FLOODING.
USUALLY WE NEED ONE EVENT TO PRIME US (BRING THE RIVERS TO BANKFULL0
AND THEN THE SECOND TO PUSH US OVER THE EDGE. AGAIN THOUGH THIS
REMAINS VERY UNCERTAIN AND LATER MODEL RUNS ARE NEEDED TO CLARIFY.


.HYDROLOGY...
A STARTER ESF ISSUED.

WE HAVE SEEN HPC'S 1155Z OUTLOOK FOR WIDESPREAD 4+ INCH RAINS IN SNE
THE NEXT 5 DAYS WITH SPOT IN EXCESS OF 6.5.

00Z AND 06Z/6 GFS ENS SIGNALS 90 PCT CONFIDENCE ON 2" MUCH OF SNE FRI
AFTN THRU SUN MORNING. ISOLATED RFALL SHOULD PEG AT LEAST 4" WHERE
TRAINING OCCURS. WE ARE SEEING GFS FCST PT RFALL OF 5" IN OUR FA BY
SUNDAY MORNING...SOME OF THIS MAY BE RELATED TO A SLIGHTLY DEEPER SFC
LOW THAN OTHER GLOBAL MODELS. STILL THE IDEA IS THERE. PERSONALLY
WONT BE SURPRISED AT ISOLATED 7" SOMEWHERE IN W OF I95.

PLEASE SEE HAYDENS LONG TERM FOR HIS ADDITIONAL DETAILS ON THE
DAILIES.

CHECK THE 06Z/6 GFS ENS PW...+4SD!!! ABOVE NORMAL! THIS IS TRULY
REMARKABLE FOR OUR AREA THIS TIME OF YEAR. AND THATS ONLY THE FIRST
SYSTEM...POSSIBLY SETTING UP ANTECEDENT CONDS FOR A RESULTANT MORE
SIGNIFICANT ADVERSE FLOOD EVENT EARLY WEEK? NOTE HOW THE GFS ENS PW
REMAIN 2SD ABV NORMAL EARLY NEXT WEEK WITH 1000-500K >565.

STILL A QUESTION ON THE SECOND OR 3RD EVENT FOR NEXT WEEK...THO THE
ECMWF OP RUN WHICH DECIDEDLY STRAYED IN THE WRONG DIRECTION MON/TUE
AS COMPARED THE GFS ENS...IS NOW JOINING THE GGEM AND GFS ENS CAMP ON
SUPPLEMENTAL HEAVY RAIN EVENTS NEXT WEEK (POTENCY MAY BE DOWN
SLIGHTLY DUE TO LOWER PW AND ASSTD COOLER THICKENSS). THIS INCLUDES
THE 12Z/6 EC WHICH JUST DOESNT BREAK DOWN THE W ATLC RIDGE AND
ASSTD DEEP SLY INFLOW.

NERFC CONTINGENCY FM YDY AND CONTD ON TRACK EARLY THIS MORNING SHOWS
NO WEEKEND GAGED RIVER FLOODING...ESP FROM RIVERS PASSING THROUGH
LOWER THAN NORMAL RESERVOIR CAPACITY...FLASHY SMALL STREAMS MAY NEED
TO BE MONITORED CLOSELY FOR AT A MINIMUM EXPECTED SHARP RISES
SATURDAY.

[aerojad]

aren't Tammy's leftovers moving south into the GOM and not up the east coast?

The LLC is, but the moisture is moving up the coast. Remember that Tammy's center was only a tiny part of the entire system. Most of the moisture from Tammy was drug north and is now being sucked up ahead of the front.

That's more important than what a LLC that's decoupled from its moisture source is going to do over Alabama and the FL panhandle.

ahh, gotcha