412  
FXUS01 KWBC 270755  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
355 AM EDT WED JUN 27 2018  
 
VALID 12Z WED JUN 27 2018 - 12Z FRI JUN 29 2018  
 
...SEVERE THUNDERSTORMS AND FLASH FLOODING POSSIBLE OVER THE  
NORTH-CENTRAL U.S. ON THURSDAY...  
 
...UNSETTLED WEATHER IN STORE FOR THE NORTHEASTERN U.S. DURING THE  
NEXT COUPLE OF DAYS...  
 
...WELL ABOVE AVERAGE TEMPERATURES TO PREVAIL ACROSS THE MIDDLE OF  
THE COUNTRY...  
 
...INCREASING THREAT FOR WILDFIRE PRODUCTION OVER THE SOUTHWESTERN  
STATES AND CENTRAL GREAT BASIN...  
 
AN ACTIVE WEATHER PATTERN AHEAD ACROSS THE NATION GIVEN A WIDE  
VARIETY OF HAZARDS IN PLAY. WHILE CONSIDERABLE ACTIVITY WILL  
UNFOLD ON WEDNESDAY, THE MORE SIGNIFICANT EVENT SHOULD WAIT UNTIL  
THE FOLLOWING DAY. AMPLIFYING FLOW ACROSS THE PACIFIC NORTHWEST  
SHOULD LEAD TO A MARKED STRENGTHENING OF A SURFACE CYCLONE  
SWINGING ACROSS THE NORTHERN HIGH PLAINS BY THURSDAY AFTERNOON. A  
MOIST AND UNSTABLE AIR MASS ACROSS THE NORTH-CENTRAL U.S. WILL  
FAVOR THE DEVELOPMENT OF NUMEROUS SHOWERS AND THUNDERSTORMS. BASED  
ON THE LATEST STORM PREDICTION CENTER OUTLOOK, SOME OF THE  
CONVECTION MAY BECOME SEVERE IN NATURE WITH AN ASSOCIATED FLASH  
FLOOD RISK. AN ENHANCED RISK FOR SEVERE THUNDERSTORMS IS CURRENTLY  
IN PLACE OVER VAST SECTIONS OF NORTH DAKOTA WITH LARGE HAIL AND  
DAMAGING WINDS THE PRIMARY THREATS. ADDITIONALLY, THE MENTIONED  
HYDROLOGIC IMPACTS ARE LIKELY AS WELL GIVEN THE STRIP OF UP TO  
2.50 INCHES OF RAINFALL ADVERTISED ACROSS NORTH DAKOTA INTO  
NORTHWESTERN MINNESOTA. DETAILS OF COURSE WILL CHANGE DURING THE  
NEXT DAY, BUT LOCALLY HEAVIER AMOUNTS ARE DEFINITELY PLAUSIBLE  
OVER THIS REGION.  
 
AN UPPER TROUGH SWEEPING ACROSS THE GREAT LAKES AND INTO NEW  
ENGLAND THE NEXT COUPLE OF DAYS WILL MAINTAIN A PERIOD OF  
UNSETTLED WEATHER. A THREAT FOR SEVERE THUNDERSTORMS IS NOTED OVER  
SECTIONS OF THE LOWER OHIO AND UPPER TENNESSEE VALLEYS GIVEN  
FAVORABLE PARAMETERS IN PLACE. FARTHER NORTH, A BROAD SHIELD OF  
SHOWERS AND THUNDERSTORMS SHOULD KEEP AREAS WET GENERALLY EAST OF  
THE MISSISSIPPI RIVER. ON A LARGER SCALE, THE HEAVIEST RAINFALL  
WILL LIKELY UNFOLD OVER NEW ENGLAND INTO THE UPPER MID-ATLANTIC  
GIVEN CLOSER PROXIMITY TO THE STRONGER DYNAMICS WITHIN THE TROUGH.  
IN ADDITION TO THE PRECIPITATION, SLIGHTLY BELOW AVERAGE  
TEMPERATURES ARE IN THE FORECAST AS HIGHS REMAIN IN THE 70S TO  
LOWER 80S ALTHOUGH MAINE CAN ANTICIPATE UPPER 60S ON THURSDAY.  
 
AS AN EXPANSIVE UPPER RIDGE BEGINS TO BUILD FROM THE FOUR CORNERS  
EASTWARD INTO THE MIDDLE OF THE COUNTRY, A MODEST HEAT WAVE WILL  
TAKE SHAPE. A NUMBER OF LOCAL FORECAST OFFICES HAVE HOISTED UP  
HEAT ADVISORIES AND EVEN AN EXCESSIVE HEAT WATCH ACROSS EASTERN  
MISSOURI AND WESTERN-CENTRAL ILLINOIS. WIDESPREAD HIGHS IN THE 90S  
ARE ANTICIPATED UNDERNEATH THIS UPPER RIDGE WHILE EVEN SOME  
POCKETS OF 100 TO 105 DEGREE READINGS ARE POSSIBLE. WHILE  
WIDESPREAD DAILY RECORDS SHOULD NOT BE BROKEN, SOME AREAS OF  
EASTERN COLORADO COULD ACHIEVE THIS FEAT ON THURSDAY, SPECIFICALLY  
DENVER AND PUEBLO.  
 
WITH HOT, DRY, AND GUSTY WINDS EXPECTED ACROSS THE SOUTHWESTERN  
U.S. AND CENTRAL GREAT BASIN, THERE WILL BE AN APPRECIABLE THREAT  
FOR WILDFIRE PRODUCTION. THE STORM PREDICTION CENTER FIRE WEATHER  
OUTLOOK NOTES A COUPLE AREAS IN THE CRITICAL THREAT LEVEL. THE  
RESULTANT LOW RELATIVE HUMIDITY AIR MASS HAS LED TO A BROAD SWATH  
OF RED FLAG WARNINGS FROM NEVADA EASTWARD INTO UTAH AND WESTERN  
COLORADO. SOME OF THESE REGIONS OVERLAP LOCATIONS OF EXTREME TO  
EXCEPTIONAL DROUGHT BASED ON THE MAP PUBLISHED A WEEK AGO.  
 
RUBIN-OSTER  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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