SPC AC 191944
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0244 PM CDT TUE MAY 19 2009
VALID 192000Z - 201200Z
...NO SVR TSTM AREAS FORECAST...
NO MAJOR CHANGES FOR 20Z UPDATE THIS AFTERNOON. PER EARLIER
DISCUSSION...WELL DEFINED UPPER VORT OVER NV WILL LIFT NEWD INTO NRN
UT WITH ENHANCED THREAT FOR DEEP CONVECTION. LATEST VIS IMAGERY
SUPPORTS THIS TREND WITH SCATTERED STRONG...HIGH BASED THUNDERSTORMS
DEVELOPING INVOF THIS FEATURE. ADDITIONALLY...A SECONDARY UPPER
VORT IS LIFTING NNEWD INTO THE 4-CORNERS REGION. SCATTERED
CONVECTION WILL BE NOTED ACROSS MUCH OF THE HIGHER TERRAIN FROM
AZ/NM...NWD INTO ERN ID/WRN WY.
FARTHER NORTH...STRONG HEATING WILL SOON AID CONVECTIVE DEVELOPMENT
ALONG ADVANCING COLD FRONT AS IT MOVES INTO WRN MT...MUCH IN LINE
WITH EARLIER THINKING. OTHERWISE...STRONG HEATING ACROSS THE CNTRL
HIGH PLAINS FROM SERN WY/NEB PANHANDLE WILL RESULT IN HIGH BASED
THUNDERSTORM ACTIVITY SPREADING/DEVELOPING NEWD INTO SWRN SD. SFC
TEMPERATURES HAVE WARMED WELL INTO THE 90S AND LAPSE RATES ARE NOW
DRY ADIABATIC. GUSTY WINDS ARE POSSIBLE WITH THIS ACTIVITY BUT WITH
PRECIPITABLE WATER VALUES SO LOW...ON THE ORDER OF .5
INCH...ORGANIZED ROBUST THUNDERSTORMS ARE NOT ANTICIPATED.
..DARROW.. 05/19/2009
.PREV DISCUSSION... /ISSUED 1120 AM CDT TUE MAY 19 2009/
...NRN INTERMOUNTAIN WEST INTO THE NRN ROCKIES/HIGH PLAINS...
PRIMARY FEATURES OF INTEREST FOR DEEP MOIST CONVECTION CONTINUE TO
BE STRONG SHORTWAVE TROUGH DIGGING INTO THE PAC NW...AND SMALLER
SYSTEM NOW OVER CENTRAL NV ROTATING AROUND LARGE UPPER HIGH. PW/S
ACROSS THE REGION ARE SEASONABLY MARGINAL FOR THUNDERSTORMS...BUT
SHOULD STILL SUPPORT SCATTERED DIURNAL DEVELOPMENT.
STRONG SURFACE-H7 COLD FRONT SHOULD BE FOCUS FOR THUNDERSTORMS OVER
THE NRN ROCKIES OF ID/WRN MT DURING THE LATE AFTERNOON. ACTIVITY
SHOULD INCREASE IN COVERAGE/INTENSITY AS FRONT AND ASSOCIATED STORMS
SHIFT EWD THROUGH THE EVENING. LAPSE RATES WILL REMAIN QUITE STEEP
AND A FEW STORMS REMAIN CAPABLE OF ISOLATED DAMAGING
WINDS/HAIL...ALTHOUGH MARGINAL LOW LEVEL MOISTURE WILL LIMIT OVERALL
INSTABILITY AND UPDRAFT STRENGTH.
ADDITIONAL CLUSTER OF STRONG STORMS SHOULD BE FOCUSED AHEAD OF
SLOWER MOVING SYSTEM MOVING ACROSS THE GREAT BASIN. HERE A FEW
GUSTS MAY APPROACH SEVERE LEVELS WITH THE STRONGER CORES GIVEN THE
VERY WARM SURFACE CONDITIONS/STEEP LOW LEVEL LAPSE RATES.
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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