Prognostic Meteorological Discussion
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000
FXUS01 KWBC 272027
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
426 PM EDT MON JUL 27 2015

VALID 00Z TUE JUL 28 2015 - 00Z THU JUL 30 2015

...COOL/UNSETTLED CONDITIONS TO PREVAIL FROM THE UPPER
INTERMOUNTAIN WEST TO THE UPPER MIDWEST...

...ABUNDANT HEAT AND HUMIDITY TO CONTINUE OVER THE SOUTHERN
PLAINS...

...MORE WET WEATHER IN STORE FOR FLORIDA THIS WEEK...


A STRONG UPPER TROUGH DIGGING INTO THE PACIFIC NORTHWEST WILL
SLIDE EASTWARD TOWARD THE NORTHERN HIGH PLAINS THE NEXT 24 HOURS.
AS THIS OCCURS, A SURFACE CYCLONE IS FORECAST TO CONTINUALLY
DEEPEN ATTAINING A RATHER LOW PRESSURE FOR THE MIDDLE OF THE
SUMMER. THIS SHOULD BE QUITE THE DYNAMIC SYSTEM WITH HEAVY
RAINFALL, SEVERE WEATHER, AND A STRONG WIND FIELD GIVEN THE LARGE
PRESSURE GRADIENT AT HAND. MOISTURE AVAILABILITY WILL NOT BE AN
ISSUE AS LARGE FLUXES OF GULF MOISTURE WILL WORK THEIR WAY UP THE
GREAT PLAINS IN ADVANCE OF THIS POWERFUL SYSTEM. A ROBUST AREA OF
CONVECTION IS EXPECTED ALONG THE LEADING COLD FRONT WITH ALL
SEVERE TYPES POSSIBLE PER THE LATEST STORM PREDICTION CENTER
OUTLOOK. MEANWHILE, A BROAD REGION OF COMMA-HEAD PRECIPITATION IS
LIKELY ON THE BACK SIDE OF THE SYSTEM WHICH COULD SUPPORT LENGTHY
PERIODS OF MODERATE TO HEAVY RAINFALL. THE FORECAST FROM WPC
SUGGESTS A WIDESPREAD 2 TO 4 INCHES OF PRECIPITATION FROM
NORTHEASTERN MONTANA INTO NORTHWESTERN NORTH DAKOTA AND EXTENDING
INTO ADJACENT PORTIONS OF SOUTHERN SASKATCHEWAN. THESE HEAVY
FORECAST AMOUNTS WILL ENHANCE THE RISK FOR FLASH FLOODING. BESIDES
THE STORMY CONDITIONS, MUCH COOLER AIR DROPPING DOWN FROM WESTERN
CANADA WILL LOWER TEMPERATURES TO 15 TO 25 DEGREES BELOW NORMAL.
HIGHS IN THE MID TO UPPER 50S ARE LIKELY THIS AFTERNOON OVER
WESTERN/CENTRAL MONTANA.

ELSEWHERE, A PROMINENT RIDGE ACROSS THE SOUTHERN PLAINS WILL
CONTINUE TO SUPPORT HOT AND HUMID CONDITIONS THROUGH MID-WEEK.
STRONG SUBSIDENCE OCCURRING UNDERNEATH THE RIDGE SHOULD SQUASH ANY
MAJOR THREAT FOR PRECIPITATION. THE EXCEPTION TO THIS RULE WILL BE
CLOSER TO THE HIGH PLAINS WHERE A LOW-LEVEL CONVERGENCE ZONE ALONG
THE LEE TROUGH MAY HELP SPARK AFTERNOON/EVENING CONVECTION.
OTHERWISE, EXPECT TEMPERATURES NEARING THE CENTURY MARK
ACCOMPANIED BY RATHER HUMID CONDITIONS.

WHILE A CORE OF THE UPPER LOW HAS WEAKENED OVER THE STATE OF
FLORIDA, THERE IS SOME REMNANT ENERGY LINGERING ACROSS THE REGION.
THESE ENERGETICS COMBINED WITH SURFACE CONVERGENCE ALONG SEA
BREEZE BOUNDARIES WILL AID IN DEEP CONVECTION, PARTICULARLY DURING
THE PEAK DIURNAL HEATING. GIVEN THE HEAVY RAINFALL IN RECENT DAYS,
FLASH FLOODING IS POSSIBLE OVER REGIONS WITH SATURATED SOILS.


RUBIN-OSTER

GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$




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