839
AWUS01 KWNH 060916
FFGMPD
WIZ000-ILZ000-IAZ000-061500-
MESOSCALE PRECIPITATION DISCUSSION 0035
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
415 AM EST FRI MAR 06 2026
AREAS AFFECTED...IA INTO NORTHERN IL AND FAR SOUTHERN WI
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 060911Z - 061500Z
SUMMARY...ISOLATED TO WIDELY SCATTERED COVERAGE OF MAINLY MINOR
FLASH FLOODING WILL BE POSSIBLE ACROSS CENTRAL/EASTERN PORTIONS OF
IA INTO NORTHERN IL AND THE IL/WI BORDER THROUGH 15Z (9 AM CST).
HOURLY RAINFALL OF 1 TO 2 INCHES WILL BE LIKELY WHERE TRAINING OF
HEAVY RAIN OCCURS WITH ISOLATED RAINFALL TOTALS OF 2 TO 3 INCHES
POSSIBLE.
DISCUSSION...REGIONAL RADAR IMAGERY AT 0845Z SHOWED ELEVATED
THUNDERSTORMS OVER CENTRAL AND SOUTHERN IA, WITH A GENERAL MOTION
TOWARD THE NORTHEAST. THE STORMS WERE LOCATED AT THE NOSE OF A
50-60 KT 850 MB JET SEEN ON AREA VAD WIND PLOTS OVER CENTRAL TO
EASTERN KS, LOCATED NORTH OF A WAVY WARM FRONT WHICH EXTENDED FROM
SOUTHEASTERN NE INTO NORTH-CENTRAL MO AND SOUTH-CENTRAL IL. THE
LOW LEVEL JET WAS RAPIDLY TRANSPORTING LOW LEVEL MOISTURE INTO THE
REGION, ALONG WITH MUCAPE VALUES OF 500-1500 J/KG TOWARD THE
NORTHEAST. BRIEF TRAINING OF CELLS HAS SUPPORTED OBSERVED RAINFALL
OF 0.75 TO 1.25 INCHES IN 30 MINUTES NEAR THE CENTRAL MO/IA BORDER
BETWEEN 07-08Z, SHOWING THE POTENTIAL FOR LOCALLY HIGH RAINFALL
TOTALS IF CELL TRAINING IS ABLE TO MAINTAIN OVER A LOCATION FOR 30
TO 60 MINUTES. A STRENGTHENING 90-100 KT UPPER LEVEL JET STREAK
WAS ALSO OBSERVED ON GOES EAST DMVS CENTERED OVER SOUTHERN MN,
PLACING IA WITHIN THE FAVORABLE RIGHT-ENTRANCE REGION.
WHILE THE MAGNITUDE OF THE LOW LEVEL JET IS LIKELY NEAR PEAK AND
RAP FORECASTS SHOW SOME WEAKENING THROUGH 12Z ACROSS EASTERN KS,
CONTINUED WARM ADVECTION DRIVEN THUNDERSTORMS ARE LIKELY TO
ADVANCE DOWNSTREAM INTO PORTIONS OF SOUTHERN WI AND NORTHERN IL
OVER THE NEXT 3-6 HOURS AS LOW LEVEL MOISTURE CONTINUES TO ADVECT
DOWNSTREAM AND UPPER LEVEL SUPPORT INCREASES. LOW LEVEL
CONVERGENCE AXES AT THE NOSE OF THE LOW LEVEL JET ARE NOT
FAVORABLY ALIGNED TO SUPPORT LONGER DURATION TRAINING OF CELLS
WITH THE MEAN STEERING FLOW FROM SW TO NE (ROUGHLY AT RIGHT ANGLES
TO LARGER CONVERGENCE AXES), BUT INCREASING CELL COVERAGE COULD
ALLOW FOR SOME BRIEF TRAINING FROM SW TO NE OR WSW TO ENE THIS
MORNING. THE POTENTIAL FOR 1 TO 2 INCHES OF RAIN IN AN HOUR AND 2
TO 3 INCHES IN 2 TO 3 HOURS WOULD SURPASS AREA-WIDE FLASH FLOOD
GUIDANCE VALUES WHICH ARE RELATIVELY LOW.
THEREFORE, A COUPLE OF INSTANCES OF LOWER-END/MINOR FLASH FLOODING
WILL BE POSSIBLE OVER THE NEXT FEW HOURS WITH IMPACTS MOSTLY
LIKELY WHERE OVERLAP OF HEAVY RAIN OCCURS WITH URBAN LOCATIONS OR
OTHER POORLY DRAINING AREAS.
OTTO
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...ARX...DMX...DVN...FSD...ILX...LOT...MKX...OAX...
ATTN...RFC...KRF...MSR...NWC...
LAT...LON 43049341 42899151 42709019 42548867 41818832
41308877 40739090 40779355 41449517 42199543
42869482
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