STORM2K

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
310 PM CDT FRI MAY 9 2003

MAY HAVE TO GET THROUGH ANOTHER ROUND OF CONVECTION AFFECTING
PORTIONS OF THE CWA TONIGHT...BEFORE POTENTIALLY SIGNIFICANT SEVERE
WX EVENT UNFOLDS FOR SAT AFTERNOON.

LATEST SFC AND MSAS ANALYSIS INDICATING OCCLUDED FRONT SWEEPING
HIGHER DEWPOINT AIR(UPPER 60S/70) EASTWARD ACRS NORTHEAST AND EAST
CENTRAL IL...BUT SAME PARAMETERS POOLING ACRS CENTRAL MO ATTM ALONG
TRAILING COLD FRONT. LATER TONIGHT PROJECTED SOUTH-SOUTHWEST H85 JET
OF AT LEAST 25 KTS TO IMPINGE ON SLIGHTLY ELEVATED THTA-E GRADIENT
OVER MO THIS EVENING...AND WITH APPROACHING INTERMEDIATE WAVE ALOFT
IN SOUTHWEST FLOW...EXPECT PRODUCTION OF NEXT ROUND OF CONVECTION
JUST TO THE SOUTH OF THE AREA OF CONCERN. BUT H85 FEED AND NORTHWARD
RETREATING H85 BAROCLINICITY MAY ALLOW CONVECTION TO BLEED ACRS THE
FAR SOUTHERN TO SOUTHEAST QUARTER OF THE CWA AS EVENING PROGRESSES.
CURRENT INDICATIONS SUGGEST LARGE HAIL AND EVEN SOME WINDS OF THE 60
TO 70 MPH VARIETY ACRS THE FAR SOUTHEAST MAY BE POSSIBLE IF STRONGER
CONVECTION MAKES IT INTO LOCAL CWA. LOCALLY HEAVY RAIN ALSO A
POSSIBILITY...BUT FEEL THREAT NOT WIDESPREAD ENOUGH TO WARRANT
FLOOD WATCH AT THIS TIME...MAY ONLY CLIP FAR SOUTHEAST FRINGE OF THE
CWA.

MAIN SHOW COMES WHEN NOW WELL ADVERTISED UPPER LOW...NOW SEEN
SPIRALING OVER THE GRT BSN...ROLLS OUT IN A NEGATIVELY TILTED FASHION
WHICH WILL EVENTUALLY CUT-OFF SAT NIGHT OVER THE UPPER MS RVR
VALLEY. LATEST SHORT RANGE MODEL ENSEMBLE SUGGESTS SFC LOW
ASSOCIATED WITH THIS FEATURE STILL TO GENERALLY STRENGTHEN OVER KS
SAT MORNING...AND PULL RIGHT UP THE MS RVR AND THE CENTRAL DVN CWA...
BOMBING AS IT PROPAGATES NORTHWARD. NGM SCARIEST(FOR US) WITH DEEPEST
AND FURTHER WEST SFC LOW PUSHING ACRS CENTRAL IA...WHILE GFS AND
UKMET FURTHEST EAST WITH LOW MOVING UP JUST EAST OF THE RIVER...
POSING MORE OF A TORNADIC THREAT FOR CENTRAL AND NORTHEAST IL.
STRENGTH OF UPPER SYSTEM SUGGESTS LOW WILL PROBABLY BE PULLED BACK UP
FURTHER WEST...ALONG AND JUST WEST OF THE MS RVR...MUCH LIKE ETA/META
MODEL INDICATES. OVERNIGHT CONVECTION AND DEBRIS FROM MO ACTIVITY
LINGERING OVER THE CWA SAT MORNING MAY BE A CONCERN FOR ITS TEMPERING
AFFECT OF DE-STABILIZATION...BUT WILL BANK ON EXPECTED DYNAMIC EXTENT
OF SYNOPTIC SCALE SYSTEM TO QUICKLY OVERCOME THIS AND PRODUCE
SIGNIFICANT SEVERE WX EVENT OVER AT LEAST THE SOUTHEAST 2/3'S OF THE
DVN CWA SAT AFTERNOON AND EVENING. IF PROJECTED ETA/META PARAMETERS
OF CAPES APPROACHING 4K J/KG AND HELICITIES OF AT LEAST 400 M2/S2 GET
CLOSE TO VERIFYING ACRS THE SOUTHEAST...AGAIN EXPECT TORNADIC
OUTBREAK AND "CRAZY" SIZE HAIL. SEE NICHOLS BLEP TECHNIQUE DERIVED
HAZARDOUS WEATHER OUTLOOK WITH ALL THE DETAILS...ALREADY ISSUED THIS
AFTERNOON. BLEP TECHNIQUE SUGGESTS IF AREAS ALONG AND SOUTH OF ROUTE
34 CORRIDOR(WARM SECTOR IN VIEW OF TRIPLE POINT)REACH 82 F OVER A SFC
DPT OF 70 DEGREES...STRAIGHT LINE WIND POTENTIAL WILL REACH 60 KTS...
AND ROTATIONAL UPDRAFT VELOCITY OF 139 KTS. THIS WOULD SUGGEST
TORNADIC STRENGTH OF UP TO A LOW END F3. IF SFC WIND INFLOW INTO THE
SUPERCELL CAN CLIMB 5 TO 7 KTS HIGHER THAN THAT USED TO CALCULATE THE
ABOVE VALUES...F4 STRENGTH TORNADOES WILL BE POSSIBLE.

EXPECT EXPLOSIVE SUPERCELLULAR DEVELOPMENT ACRS FAR NORTHEAST MO
SAT AFTERNOON...WITH CELLS MOVING NORTHEAST INTO THE SOUTHERN CWA.
OTHER SUPERCELLS MAY FORM RIGHT OVER THE LOCAL CWA(FAR SOUTHEAST
IA/NORTHEAST MO/WEST CENTRAL IL) BY MID AFTERNOON. AGAIN SEE THE
HWO FOR TIMING DETAILS.

AS SFC SYSTEM CONTINUES TO BOMB OVER WI ON SUNDAY...EXPECT ENOUGH OF
A PRESSURE GRADIENT TO INDUCE POSSIBLE ADVISORY TYPE WESTERLY
WINDS...WITH TEMPS NOT RECOVERING OUT OF THE 50S IN STRONG WRAP
AROUND.

LONGER RANGE(MON-FRI)...WILL SIDE WITH LATEST ECMWF AND UKMET FOR
EXTENDED PERIOD. CUT OFF UPPER SYSTEM PULLS AWAY EAST OF THE AREA
MONDAY...BUT STILL CLOSE ENOUGH FOR LINGERING COLD POOL TO TREND
TOWARD UNDERCUTTING LATEST MEX HIGHS FOR MONDAY. THE MIDWEST THEN
BECOMES UNDER THE INFLUENCE OF UPPER AND SFC RIDGING FOR DRY BUT
SLOWLY MODERATING TEMPERATURE TREND THROUGH WED. PREVALENT(THIS
SPRING) EAST-NORTHEAST SFC FLOW/LAKE EFFECT TO KEEP TEMPS ON
COOLER SIDE THROUGH WED...GENERALLY 60S. MRF DROPS DISTURBANCE IN ON
WEST-NORTHWEST FLOW FOR PRECIP CHANCE LATE WED INTO THU...WHILE UKMET
AND EURO SLOWER AND MUCH FURTHER SOUTHWEST WITH A SOUTHERN STREAM CUT
OFF PUSHING TOWARD THE SOUTHERN PLAINS BY THU. WILL PLAY MRF ODD
MODEL OUT AND KEEP CWA DRY UNTIL THU NIGHT AND FRI WHEN AT LEAST
SOUTH HALF OF CWA MAY GET CLIPPED BY OVERRUNNING RAIN OFF THIS
SOUTHERN STREAM SYSTEM.

OMG ... I didn't even finish reading that and already I'm worried for her. :o

STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK
DAY 2 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWI47 KWNS.

VALID 101200Z - 111200Z

THERE IS A MDT RISK OF SVR TSTMS FOR ERN MO...IL...INDIANA...SRN LOWER MI...EXTREME SE WI...AND WRN OH TO THE RIGHT OF A LINE FROM 25 SW EVV 35 ESE POF 20 SSE UNO 45 NE COU 40 E DBQ 10 WNW MKE 20 ESE MKG 10 SSW LAN 15 SSW DTW 10 SE MFD 20 W UNI 30 WSW LUK 25 SW EVV.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 E ILM 20 SW RDU 45 S PSK 35 W TRI 30 NW HSV 15 NNW HEZ 55 S LFK 20 SE CLL 45 N CLL 45 SSE DAL 20 NNW PRX 35 SW UMN 20 WNW SZL 20 NE DSM 10 S LSE 50 NE GRB 25 SE APN ...CONT... 25 SW BUF 15 N IPT 15 ESE NEL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 10 E U31 30 NNW MHS 25 SSW EUG 15 NE PDX 30 W ALW 35 NE MQM 30 SSE LND FCL 40 NNW LIC 20 SSE PUB 30 WSW ALS 45 N BCE 45 SSE ELY 10 E U31.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 N SYR 15 ESE ISP...CONT... CRE 35 SSE CLT 35 NW AND 25 ENE ANB 25 S MEI 20 ENE BTR 40 SSE LCH ...CONT... 45 SSE VCT 25 WSW NIR 25 ESE HDO 50 S SEP DUA 35 WSW JLN 20 SW FNB 25 NNW SUX 50 SE FAR 10 NE INL.

...MID MS/OH VALLEY AREA...
LARGE SCALE PATTERN APPEARS FAVORABLE FOR AN EXTENSIVE SEVERE WEATHER OUTBREAK ACROSS THE MID MS/OH VALLEY AREA ON SATURDAY. A STRONG SHORTWAVE TROUGH NOW OVER NV/UT WILL MOVE EWD TO THE CENTRAL HIGH PLAINS BY LATE TONIGHT...THEN CONTINUE ENEWD OVER THE MID MS VALLEY TO THE OH VALLEY/GREAT LAKES BY TOMORROW NIGHT. AN ASSOCIATED SURFACE LOW INVOF ERN KS WILL MOVE NNEWD TO WI/UPPER MI AND DEEPEN RAPIDLY BY EVENING...AND A COLD FRONT S OF THE LOW WILL SURGE EWD ACROSS THE MID MS VALLEY BY TOMORROW NIGHT. RICH LOW-LEVEL MOISTURE IN THE WARM SECTOR WILL SPREAD NWD ACROSS THE OH VALLEY/IL/INDIANA IN THE WAKE OF MORNING WAA STORMS...AND CONTRIBUTED TO THE DEVELOPMENT OF STRONG INSTABILITY IN THE WARM SECTOR BY AFTERNOON /MLCAPE VALUES OF 1500-3000 J/KG/.

EXPECT A BAND OF SEVERE STORMS TO DEVELOP DURING THE AFTERNOON ALONG THE COLD FRONT FROM ERN MO INTO WRN IL...AND STORMS SHOULD THEN SPREAD QUICKLY EWD OVERNIGHT. STRONG LINEAR FORCING... SOMEWHAT UNIDIRECTIONAL PROFILES...AND 0-6 KM SHEAR VECTORS ROUGHLY PARALLEL TO THE COLD FRONT MAY TEND TO FAVOR THE DEVELOPMENT OF A SQUALL LINE WITH WIDESPREAD DAMAGING WINDS AND HAIL. HOWEVER... INSTABILITY AND DEEP LAYER SHEAR WILL BE FAVORABLE FOR SUPERCELLS IN THE WARM SECTOR AHEAD OF THE SQUALL LINE...AS WELL AS IN THE EARLY STAGES OF DEVELOPMENT. THE TORNADO THREAT WILL DEPEND HEAVILY ON THE OCCURRENCE OF MORE DISCRETE SUPERCELLS DURING THE EVENING NEAR AND E OF THE SURFACE LOW.

..THOMPSON.. 05/09/03

NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED FOR 1730Z

Here's the actual chart for which all the foreign language stands for. (I know its not foreign language...its wx abbreviations)

I know people online who live in Indiana! :o That's not good! :o

Yea this includes my area as well!!!!.....

Then you stay safe too WxBud! I want to see ya in one piece on Monday!