618  
FOUS30 KWBC 151922  
QPFERD  
 
EXCESSIVE RAINFALL DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
222 PM EST FRI NOV 15 2024  
 
DAY 1  
VALID 16Z FRI NOV 15 2024 - 12Z SAT NOV 16 2024  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
ORRISON  
 
DAY 2  
VALID 12Z SAT NOV 16 2024 - 12Z SUN NOV 17 2024  
 
THE PROBABILITY OF RAINFALL EXCEEDING FLASH FLOOD GUIDANCE IS LESS  
THAN 5 PERCENT.  
 
CAMPBELL  
 
DAY 3  
VALID 12Z SUN NOV 17 2024 - 12Z MON NOV 18 2024  
 
...THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FOR PORTIONS OF  
THE SOUTHERN PLAINS...  
 
20Z UPDATE: ONLY MADE MINOR CHANGES TO THE INHERITED MARGINAL AND  
SLIGHT RISK AREA OVER TX INTO OK AS THE FORECAST LOOKS ON TRACK.  
VERY IMPRESSIVE IVT, PWS AND FORCING WILL MOVE ACROSS TX/OK BY  
SUNDAY EVENING INTO THE OVERNIGHT HOURS. THIS SHOULD BE ENOUGH TO  
OVERCOME THE LIMITED FORECAST INSTABILITY AND RESULT IN DEEP  
CONVECTION AND HEAVY RAINFALL RATES. THE LATEST MODEL CONSENSUS IS  
FOR 2-4" OF RAIN, BUT WOULD EXPECT ISOLATED SWATHS AS HIGH AS 4-6"  
WITHIN THIS SETUP. THE OVERALL PROGRESSIVE NATURE OF THE SYSTEM AND  
LIMITED INSTABILITY WILL CAP THE UPPER BOUND OF RAINFALL  
TOTALS...BUT THIS SYSTEM IS DYNAMIC ENOUGH WITH PLENTIFUL MOISTURE  
TO SUGGEST AT LEAST LOCALIZED FLASH FLOODING IS LIKELY.  
 
THE MARGINAL RISK OVER WESTERN OR ALSO REMAINS. THIS RISK IS PRETTY  
BORDERLINE, AS THE AR IS ONLY WEAK TO MODERATE AND IS FAIRLY  
PROGRESSIVE. HOWEVER EVENT TOTAL RAIN OF 2-4" (THROUGH 12Z MON)  
AND HOURLY RAINFALL RATES POSSIBLY APPROACHING 0.5" WITHIN A  
NARROW SOUTHWARD SHIFTING AXIS SUGGEST THAT SOME MINOR FLOODING  
ISSUES COULD ARISE ALONG COASTAL AREAS/MOUNTAINS.  
 
CHENARD  
   
..PREVIOUS DISCUSSION  
 
AN UPPER TROUGH TRAVERSING THROUGH THE WEST THIS WEEKEND IS  
EXPECTED TO SPLIT WHICH WILL SEND ENERGY IN THE NORTHERN  
PLAINS/UPPER MIDWEST ALONG WITH A STRONG SOUTHERN STREAM CUTOFF LOW  
INTO THE FOUR CORNER THAT WILL EXIT INTO THE CENTRAL/SOUTHERN  
PLAINS FOR THE START OF THE WEEK. A SURFACE LOW PRESSURE SYSTEM  
WILL FORECAST TO SPIN UP IN THE LEE OF THE ROCKIES AND DEEPEN AS IT  
TRACKS FROM THE PLAINS THROUGH THE MIDWEST. SCATTERED TO WIDESPREAD  
MODERATE TO HEAVY RAINFALL WILL BE SUPPORTED BY THIS SETUP ACROSS  
PORTIONS OF THE SOUTHERN ROCKIES AND THE ADJACENT SOUTHERN/CENTRAL  
PLAINS.  
 
GUIDANCE IS SUGGESTING 1 TO 2 INCHES OF RAIN FOR CENTRAL AND  
EASTERN PORTIONS OF NEW MEXICO, PARTICULARLY OVER SOME OF THE SAME  
AREAS THAT HAD SEVERAL INCHES OF SNOW LAST WEEK. WITH RAIN ON TOP  
OF SNOW EXPECTED SOME LOCATIONS WILL HAVE AN INCREASED RISK FOR  
FLOODING CONCERNS. THE MARGINAL RISK AREA THAT WAS ALREADY IN  
EFFECT WAS EXPANDED WESTWARD TO NOW COVER CENTRAL AND EASTERN  
PORTIONS OF NEW MEXICO. THE HIGHEST CONCENTRATION OF RAINFALL WILL  
LIKELY FOCUS ACROSS PARTS OF NORTHERN TEXAS/PANHANDLE INTO WESTERN  
OKLAHOMA. CONSENSUS SUGGESTS AREAL AVERAGE OF 3 TO 4.5 INCHES WITH  
LOCALLY HIGHER AMOUNTS POSSIBLE. THEREFORE, A SLIGHT RISK WAS  
INTRODUCED WITH THIS ISSUANCE.  
 
CAMPBELL  
 
DAY 1 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/94EPOINTS.TXT  
DAY 2 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/98EPOINTS.TXT  
DAY 3 THREAT AREA: HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/99EPOINTS.TXT  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab HPC Page
Main Text Page