HPC Short Range Forecast Discussion

Hydrometeorological Prediction Center

SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
436 AM EDT TUE MAY 22 2012

VALID 12Z TUE MAY 22 2012 - 12Z THU MAY 24 2012

...A DEEP UPPER TROUGH WILL ENCOMPASS MUCH OF THE NORTHWESTERN
U.S. BRINGING COOL AND UNSETTLED CONDITIONS TO THE REGION...

...AS ENERGY ALOFT SPREADS FROM THE WEST INTO THE MIDDLE OF THE
NATION...SEVERE WEATHER WILL BE POSSIBLE OVER THE NORTHERN
PLAINS...

...RED FLAG WARNINGS SHOULD CONTINUE TO BLANKET MUCH OF THE
SOUTHWESTERN PORTION OF THE COUNTRY INDICATING AN ENHANCED RISK
FOR WILDFIRES...


THE MAIN FEATURE IMPACTING THE COUNTRY THIS WEEK IS A DEEP UPPER
TROUGH WHICH IS EXPECTED TO SPAN A LARGE SECTION OF THE
NORTHWESTERN U.S. BY THURSDAY MORNING...THE UPPER TROUGH SHOULD
ENCOMPASS A REGION STRETCHING FROM THE PACIFIC NORTHWEST ALL THE
WAY TO THE NORTHERN PLAINS. STRONG DYNAMICS ALOFT WILL SUPPORT
WIDESPREAD PRECIPITATION OVER THIS OUTLINED AREA WITH OROGRAPHIC
EFFECTS AIDING IN FURTHER ACCUMULATIONS OVER THE MOUNTAINOUS WEST.
GIVEN THE COLD NATURE OF THIS SYSTEM...SOME OF THE HIGHER MOUNTAIN
PEAKS MAY GET SOME SNOW OUT OF THESE ARRAY OF DISTURBANCES. AS THE
LEAD ENERGY RACES TOWARD THE NORTHERN PLAINS...IT SHOULD BEGIN
ENCOUNTERING AN INCREASINGLY MOIST AND UNSTABLE AIR MASS
SUPPORTIVE OF ORGANIZED CONVECTION. SOME OF THE STORMS MAY BECOME
SEVERE WITH LARGE HAIL AND DAMAGING WINDS BEING THE PRIMARY
THREATS. IN TERMS OF TEMPERATURES...HIGHS ARE FORECAST TO STRUGGLE
TO GET OUT OF THE 50S ON WEDNESDAY OVER THE UPPER INTERMOUNTAIN
WEST AND NORTHERN ROCKIES.

LOOKING FARTHER TO THE SOUTH...RED FLAG WARNINGS CURRENTLY COVER A
LARGE SECTION OF THE DESERT SOUTHWEST...CENTRAL GREAT BASIN...AND
FOUR CORNERS REGION WITH SUCH ISSUANCES REMAINING IN EFFECT THE
NEXT DAY OR SO. THE RESULT WILL BE AN ENHANCED THREAT FOR
WILDFIRES GIVEN THE WARM...DRY...AND WINDY CONDITIONS IN THE
FORECAST. THE STORM PREDICTION CENTER FIRE WEATHER OUTLOOK
CURRENTLY OUTLINES A REGION FROM THE DESERT SOUTHWEST OFF TO THE
FOUR CORNERS REGION THROUGH THURSDAY FOR ENHANCED FIRE DANGER.

A VERY SLOW MOVING ELONGATED UPPER TROUGH CONTINUES TO IMPACT THE
EAST COAST. ACCOMPANYING THIS ENERGY IS A DIFFUSE SURFACE BOUNDARY
WITH MEAGER CONVERGENCE ALONG IT WHICH SHOULD LEAD TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HOWEVER...THE WEAK NATURE OF
THIS BOUNDARY SHOULD LIMIT THE EXTENT OF CONVECTION. WELL TO THE
SOUTH OF THIS REGION...CONDITIONS LOOK BETTER FOR HEAVY RAINFALL
PRODUCTION OVER SOUTHERN SECTIONS OF FLORIDA AS ABUNDANT MOISTURE
EMERGES FROM THE CARIBBEAN. IT APPEARS THE HEAVIEST RAINS SHOULD
OCCUR OVER CUBA WITH TOPOGRAPHY PLAYING A LEAD ROLE.




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