812  
FXUS01 KWBC 172036  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
435 PM EDT MON JUN 17 2024  
 
VALID 00Z TUE JUN 18 2024 - 00Z THU JUN 20 2024  
 
...A HEAT WAVE BEGINS TO SETTLE IN OVER THE GREAT LAKES, OHIO  
VALLEY AND THE NORTHEAST TODAY, CONTINUING THROUGH MIDWEEK...  
 
...SIGNIFICANT HEAVY RAIN/FLASH FLOODING THREAT FOR THE TEXAS GULF  
COAST LATER TUESDAY AND ESPECIALLY WEDNESDAY ASSOCIATED WITH  
POTENTIAL T.C. ONE...  
 
...HEAVY RAIN AND SEVERE THUNDERSTORMS POSSIBLE TUESDAY/WEDNESDAY  
FROM THE UPPER MIDWEST INTO THE CENTRAL PLAINS...  
 
...LATE-SEASON WET SNOW WILL PERSIST ACROSS THE HIGH-ELEVATIONS OF  
THE NORTHERN ROCKIES FOR THE NEXT COUPLE OF DAYS...  
 
AN ACTIVE WEEK IS IN STORE ACROSS THE U.S. AS A HEAT WAVE BUILDS  
OVER THE GREAT LAKES/OHIO VALLEY/NORTHEAST, MULTIPLE AREAS OF  
FLASH FLOODING AND SEVERE WEATHER IMPACT THE CENTRAL U.S., AND  
EVEN SOME LATE SEASON SNOW CONTINUES IN THE NORTHERN ROCKIES. A  
STRONG UPPER-LEVEL HIGH WILL CONTINUE TO BUILD IN OVER THE GREAT  
LAKES/NORTHEAST, BRINGING THE FIRST SIGNIFICANT HEAT WAVE OF THE  
SEASON TO THE REGION. FORECAST HIGHS TUESDAY AND WEDNESDAY WILL  
REACH INTO THE MID- TO UPPER 90S, EVEN WELL INTO NORTHERN NEW  
ENGLAND. WIDESPREAD, NUMEROUS RECORD-TYING/BREAKING HIGH  
TEMPERATURES ARE POSSIBLE. ADDITIONALLY, MORNING LOWS WILL REMAIN  
IN ABOUT THE MID-70S, AT RECORD-TYING/BREAKING LEVELS, PROVIDING  
LITTLE RELIEF FROM THE HEAT OVERNIGHT. THE EARLY ARRIVAL OF THIS  
MAGNITUDE OF HEAT, THE DURATION, ABUNDANT SUNSHINE, AND LACK OF  
RELIEF OVERNIGHT WILL INCREASE THE DANGER OF THIS HEATWAVE BEYOND  
WHAT THE EXACT TEMPERATURE VALUES WOULD SUGGEST. THIS IS  
ESPECIALLY TRUE FOR THOSE WITHOUT ADEQUATE AIR CONDITIONING, WHICH  
BECOMES MORE OF A CONCERN FOR LOCATIONS FURTHER NORTH THAT ARE NOT  
AS ACCUSTOMED TO PERIODS OF PERSISTENT, INTENSE HEAT.  
 
ANOTHER BIG WEATHER STORY OVER THE NEXT COUPLE OF DAYS WILL BE A  
SIGNIFICANT PLUME OF TROPICAL MOISTURE FLOWING NORTHWARD INTO THE  
SOUTH-CENTRAL U.S. ALONG THE WESTERN SIDE OF THE RIDGE AND  
ACCOMPANYING HEAVY RAIN/FLASH FLOODING THREATS. FIRST, REPEATED  
ROUNDS OF SCATTERED, INTENSE DOWNPOURS WILL CONTINUE THROUGH  
MONDAY NIGHT ALONG PORTIONS OF THE CENTRAL GULF COAST AS  
THUNDERSTORMS FEED OF THE INCOMING TROPICAL MOISTURE. A SLIGHT  
RISK (LEVEL 2/4) OF EXCESSIVE RAINFALL IS IN EFFECT FOR THE THREAT  
OF SCATTERED FLASH FLOODING. THEN, MORE WIDESPREAD THUNDERSTORMS  
WILL BEGIN TO SPREAD INTO PORTIONS OF THE CENTRAL/WESTERN GULF  
COAST LATER TUESDAY AND CENTRAL/SOUTH TEXAS BY WEDNESDAY  
ASSOCIATED WITH THE APPROACH OF POTENTIAL T.C. ONE. MODERATE RISKS  
(LEVEL 3/4) OF EXCESSIVE RAINFALL ARE IN EFFECT FOR THESE REGIONS  
WITH FORECAST AREAL AVERAGE RAINFALL OF 3"+, AND LOCALLY HIGHER  
TOTALS OF 5-15" EXPECTED, ESPECIALLY FOR AREAS CLOSER TO THE  
COAST. RAIN RATES MAY BE TORRENTIAL AT TIMES, APPROACHING 3"+ PER  
HOUR. THIS WILL BRING THE THREAT FOR POTENTIALLY NUMEROUS  
INSTANCES OF FLASH FLOODING. A MORE CONDITIONAL THREAT MAY EXPAND  
INTO PORTIONS OF NORTH TEXAS WEDNESDAY, AND WHILE RAINFALL TOTALS  
ARE NOT EXPECTED TO BE AS HIGH, SOME FLASH FLOODING WILL ALSO BE  
POSSIBLE THROUGH THE RIO GRANDE VALLEY. IN ADDITION TO THE HEAVY  
RAINFALL, SOME COASTAL FLOODING AND GUSTY WINDS CAN ALSO BE  
EXPECTED. SEE THE LATEST ADVISORY FROM THE NATIONAL HURRICANE  
CENTER FOR ADDITIONAL DETAILED UPDATES.  
 
FURTHER NORTH, ADDITIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE  
EXPECTED AS THE INFLUX OF MOISTURE CONTINUES TO INTERACT WITH A  
WAVY FRONTAL BOUNDARY DRAPED ACROSS PORTIONS OF THE  
NORTHERN/CENTRAL PLAINS AND UPPER MIDWEST. A BROAD AREA OF SHOWERS  
AND THUNDERSTORMS WILL CONTINUE THROUGH MONDAY EVENING ALONG AND  
AHEAD OF THE FRONT AS IT SLOWLY LIFTS NORTHWARD. A SLIGHT RISK OF  
EXCESSIVE RAINFALL IS IN EFFECT OVER PORTIONS OF THE NORTHERN  
PLAINS/UPPER MIDWEST WHERE THE AVAILABLE MOISTURE, AS WELL AS  
IMPRESSIVE UPPER-LEVEL DYNAMICS ASSOCIATED WITH AN APPROACHING  
TROUGH, MAY LEAD TO SOME HEAVIER RAIN RATES (2" PER HOUR) AND  
SCATTERED FLASH FLOODING, ESPECIALLY IN URBAN AREAS. A SLIGHT RISK  
OF SEVERE WEATHER (LEVEL 2/5) IS ALSO IN EFFECT FROM THE STORM  
PREDICTION CENTER, SPREADING FURTHER WESTWARD INTO THE  
NORTHERN/CENTRAL HIGH PLAINS, FOR SOME LARGE HAIL, DAMAGING WINDS,  
AND A FEW TORNADOES. THE FRONT WILL BEGIN TO PUSH BACK  
SOUTHEASTWARD AS A COLD FRONT TUESDAY AHEAD OF THE APPROACHING  
TROUGH BEFORE STALLING OUT THROUGH THE MIDDLE MISSISSIPPI/MISSOURI  
VALLEYS AHEAD OF THE EASTERN RIDGE BY TUESDAY NIGHT. SLIGHT RISKS  
OF EXCESSIVE RAINFALL ARE OUTLINED FROM THE UPPER MIDWEST  
SOUTHWEST THROUGH THE MIDDLE MISSOURI VALLEY INTO THE CENTRAL  
PLAINS TUESDAY, AND AGAIN FOR THE MIDDLE MISSOURI VALLEY  
WEDNESDAY. ADDITIONAL ROUNDS OF STORMS ALONG AND AHEAD OF THE  
FRONT WILL HAVE THE TENDENCY TO REPEAT/BACK-BUILD OVER THE SAME  
AREAS ALONG THE STALLING FRONT, INCREASING THE POTENTIAL FOR  
LOCALLY HEAVY RAIN TOTALS AND SOME SCATTERED FLASH FLOODING. THERE  
IS ALSO A SLIGHT RISK OF SEVERE WEATHER TUESDAY OVER THE SAME  
REGION AS SOME STORMS MAY PRODUCE LARGE HAIL/DAMAGING WINDS.  
 
TO THE WEST, THE UNSEASONABLY STRONG UPPER-LEVEL SYSTEM WILL ALSO  
CONTINUE TO BRING AN INTRUSION OF MUCH COOLER, BELOW AVERAGE AIR  
INTO PORTIONS OF THE NORTHERN/CENTRAL PLAINS/ROCKIES AND GREAT  
BASIN. FORECAST HIGHS ON TUESDAY WILL BE IN THE 50S AND 60S IN THE  
NORTHERN ROCKIES/HIGH PLAINS, WITH SOME LOW 70S INTO THE GREAT  
BASIN. IN ADDITION, FORECAST MORNING LOWS ON TUESDAY IN THE LOW TO  
MID-30S THROUGHOUT MUCH OF THE GREAT BASIN HAVE PROMPTED  
FROST/FREEZE-RELATED WARNINGS AND ADVISORIES. TEMPERATURES SHOULD  
RECOVER A BIT WEDNESDAY FOR THE GREAT BASIN AND NORTHERN ROCKIES  
WHILE PORTIONS OF THE CENTRAL PLAINS DROP INTO THE 60S FOLLOWING  
THE COLD FRONT PASSAGE. AREAL SHOWERS AND THUNDERSTORMS WITH SOME  
MODERATE RAINFALL WILL ALSO LINGER OVER THE NORTHERN ROCKIES/HIGH  
PLAINS MONDAY EVENING AND INTO THE DAY TUESDAY BEFORE TAPERING OFF  
BY LATER TUESDAY NIGHT. WINTER-WEATHER RELATED WARNINGS AND  
ADVISORIES REMAIN IN EFFECT AS MODERATE TO HEAVY SNOW CONTINUES  
FOR HIGHER MOUNTAIN ELEVATIONS. WHILE MOST OF THE ACCUMULATING  
SNOW SHOULD REMAIN ABOVE ABOUT 6000-7000 FEET, SOME OF THE HIGHER  
VALLEYS MAY SEE SOME FLAKES MIX IN.  
 
PUTNAM  
 
GRAPHICS AVAILABLE AT  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  
 

 
 
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