SPC AC 111300
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0800 AM CDT TUE MAY 11 2004
VALID 111300Z - 121200Z
THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 NNW
CMX 30 SSW MCW 30 SE LNK 45 N P28 60 NW ABI 35 NNW BGS 45 WSW LBB 40
ESE LAA 35 SE SNY 30 W CDR 40 WSW REJ 45 SSW DIK 60 NNE DVL.
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SSW ART 10 S HUL
...CONT... 20 SW WAL 15 WSW SOP 35 ESE CAE 35 ENE SAV ...CONT... 25
SE JAX 15 S PIE ...CONT... 80 SSE MRF 10 SSE HOB 20 S AKO FCL 35 S
CAG 30 W GJT 30 NW CDC 40 W TPH 40 W U31 OWY 55 N GGW.
...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN PLAINS / UPPER MS
VALLEY SWD INTO THE SRN HIGH PLAINS...
...SYNOPSIS...
MAIN UPPER TROUGH OVER THE GREAT BASIN ATTM IS FORECAST TO
STRENGTHEN WHILE MOVING SLOWLY EWD ACROSS THE ROCKIES THROUGH THE
PERIOD. AS HEIGHT FALLS SPREAD ACROSS THE PLAINS...LOW NOW OVER WY
SHOULD DEEPEN / MOVE EWD INTO THE PLAINS ALONG WITH ATTENDANT
FRONTAL SYSTEM. THIS LOW AND ASSOCIATED BOUNDARIES SHOULD PROVIDE
THE FOCUS FOR SEVERE STORM DEVELOPMENT THIS AFTERNOON.
...NRN PLAINS / UPPER MS VALLEY SWD INTO THE SRN HIGH PLAINS...
CLUSTERS OF CONVECTION CONTINUE ATTM ACROSS THE PLAINS IN BROAD
REGION OF WARM ADVECTION AHEAD OF UPPER TROUGH. THESE CLUSTERS
SHOULD CONTINUE MOVING NEWD...WHILE IN THE WAKE OF THIS CONVECTION
AIRMASS DESTABILIZATION WILL BEGIN ACROSS THE PLAINS.
BY MID-AFTERNOON...STORMS SHOULD DEVELOP INVOF SURFACE LOW / DRYLINE
/ COLD FRONT INTERSECTION INVOF WRN SD / THE NEB PANHANDLE. WITH
TIME...STORMS SHOULD INCREASE / SPREAD EWD INTO MODERATELY UNSTABLE
AIRMASS /1500 TO 2500 J/KG MEAN-LAYER CAPE/.
STRONGER SWLY MID-LEVEL FLOW WILL CONTINUE TO SPREAD EWD OVER THIS
REGION AHEAD OF UPPER TROUGH...AND WITH STRONG SLY LOW-LEVEL
FLOW...DEEP-LAYER SHEAR PROFILES WILL BECOME INCREASINGLY FAVORABLE
FOR SUPERCELLS. LARGE HAIL AND DAMAGING WINDS CAN BE
EXPECTED...ALONG WITH THE POTENTIAL FOR A COUPLE OF TORNADOES.
OVERNIGHT...COLD FRONT IS FORECAST TO MOVE SEWD ACROSS THE NRN AND
INTO THE CENTRAL PLAINS. STORMS SHOULD TREND TOWARD LINEAR
ORGANIZATION WITH TIME...WHICH MAY INCREASE THE THREAT FOR DAMAGING
WINDS. SEVERE THREAT SHOULD CONTINUE THROUGH THE NIGHT...WITH
STORMS SPREADING AS FAR NEWD AS THE UPPER MS VALLEY / WRN GREAT
LAKES REGION AS LOW SHIFTS RAPIDLY NEWD.
...CENTRAL TX...
PRONOUNCED MCV IS MOVING NEWD ACROSS CENTRAL TX ATTM WITHIN BROAD
ZONE OF WARM ADVECTION. ALTHOUGH INSTABILITY SHOULD REMAIN LIMITED
THROUGHOUT THE DAY ACROSS MOST OF THIS REGION...STORMS WILL LIKELY
INCREASE THROUGH THE AFTERNOON AHEAD OF THIS FEATURE.
MODERATELY-STRONG / VEERING LOW-LEVEL WIND FIELD COMBINED WITH MOIST
LOW-LEVEL AIRMASS /NEAR 70 DEWPOINTS/ SUGGEST A THREAT FOR AN
ISOLATED / BRIEF TORNADO OR TWO. HOWEVER...DEEP-LAYER SHEAR SHOULD
REMAIN LIMITED SUCH THAT LONG-LIVED STORMS ARE NOT ANTICIPATED.
...OH VALLEY / SRN NEW ENGLAND AND VICINITY...
COLD FRONT IS FORECAST TO MOVE SLOWLY SWD ACROSS THIS REGION
TODAY...WITH AIRMASS EXPECTED TO BECOME MARGINALLY UNSTABLE BY
AFTERNOON. ALTHOUGH MID-LEVEL SHORT-WAVE RIDGING ACROSS A LARGE
PORTION OF THIS REGION SHOULD SUPPRESS THUNDERSTORM DEVELOPMENT TO
SOME DEGREE...SCATTERED TO ISOLATED STORMS ARE FORECAST TO DEVELOP.
ALTHOUGH GENERALLY WEAK DEEP-LAYER WIND FIELD IS FORECAST...DEGREE
OF INSTABILITY SUGGESTS THAT LOCALLY DAMAGING WINDS OR MARGINAL HAIL
WILL BE POSSIBLE WITH STRONGER STORMS.
..GOSS.. 05/11/2004
...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3. THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 1630Z
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