975
FXUS63 KGRR 160019
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
819 PM EDT MON JUL 15 2019
LATEST UPDATE...
UPDATE/SYNOPSIS/AVIATION
SYNOPSIS
ISSUED AT 820 PM EDT MON JUL 15 2019
- PARTLY CLOUDY TONIGHT
- REMNANTS OF BARRY COULD BRING HEAVY RAIN TO AREAS NEAR I-69
TUESDAY INTO EARLY WEDNESDAY
- HEAT RETURNS THURSDAY THROUGH SATURDAY, IT IS LIKELY THOSE 3
DAYS WILL BE THE HOTTEST OF THE SUMMER SO FAR.
UPDATE
ISSUED AT 820 PM EDT MON JUL 15 2019
THE SHOWERS ASSOICATED WITH THE WARM FRONT HAVE PUSHED EAST OF
THE AREA. IT WOULD NOT OUT OF THE QUESTION THEE STORMS OVER
NORTHERN LAKE MICHIGAN COULD BRUSH THE AREA NORTH OF ROUTE 10
EARLY TONIGHT BUT FOR THE MOST PART IT SHOULD STAY DRY.
I AM VERY CONCERNED ABOUT THE REMNANTS OF T.D. BARRY MOVING INTO
OUR CWA TUESDAY. WE HAVE A LARGE AREA OF PRECIPITABLE WATER VALUES
OVER 2 INCHES COMING INTO THE I-94 AREA TOMORROW AND THE MODELS
TEND TO UNDERPLAY THESE EVENTS. THE HREF PROBABILITY MATCH MEAN
SHOWS FOR 24 HOUR RAINFALL HAS AREAS OVER 2 INCHES IN THE I-69
AREA BY 8 AM TUESDAY. AREAS OF UP TO AN INCH ARE AS FAR NORTHWEST
AS SOUTHERN KENT COUNTY. THIS WILL HAVE TO BE WATCHED FOR SURE.
ANOTHER DISTURBING ASPECT TO THIS IS THE MODEL SOUNDING FOR OUR SE
CWA TOMORROW AFTERNOON. THE RAP MODEL SHOWS NEARLY 2500 J/KG OF
CAPE WITH THE EQUILIBRIUM LEVEL NEAR THE TROPOPAUSE (45,0000 FT).
THERE IS NO CIN. ON TOP OF THAT THE LCL IS AROUND 1500 FT. GIVEN
THE WATER IN THE AIR (OVER 2 INCHES / MORE THAN 2 STANDARD
DEVIATIONS FROM CLIMO) AND ALL THAT CAPE, THESE COULD BE SOME
VERY WET THUNDERSTORMS. IT SHOULD BE NOTED WE ARE IN THE MARGINAL
RISK FOR EXCESSIVE RAIN TOMORROW, SOUTH OF A LINE FROM SOUTH HAVEN
TO LANSING. THIS SOMETHING WE WILL HAVE TO WATCH CLOSELY.
DISCUSSION
(THIS EVENING THROUGH NEXT MONDAY)
ISSUED AT 318 PM EDT MON JUL 15 2019
THE AXIS OF INSTABILITY WAS PIVOTING EASTWARD THROUGH THE CWA AT
THIS TIME. THE STORMS CONTINUE TO ROLL EAST. IT APPEARS THERE WILL
BE A BREAK IN THE ACTIVITY ONCE THEY CLEAR THE MT PLEASANT TO
JACKSON REGION BY ABOUT 430 PM.
THE TROPICAL MOISTURE LIFTING NORTHWARD THROUGH THE MS VALLEY WILL
MOVE INTO SOUTHERN LOWER MI. IT DOES LOOK LIKE THE DEEP MOISTURE
WILL RESULT IN NUMEROUS SHOWERS AND PERHAPS A FEW STORMS ON
TUESDAY. THE GREATEST POTENTIAL WILL BE SOUTH OF A GRAND RAPIDS TO
ALMA LINE. THERE IS AN INCREASED RISK THAT THE RAIN COULD BE
HEAVY...WHICH WILL NEED TO BE MONITORED.
IMPRESSIVE HEAT MOVES IN FOR THURSDAY INTO SATURDAY. THE AREA WILL
BE IN THE BAROCLINIC ZONE SO SOME STORMS ARE EXPECTED AS WELL.
NORTHERN PARTS OF THE CWA MAY SEE THERE TEMPERATURES IMPACTED BY
THE CLOUDS/STORM SO WE ARE LESS CERTAIN OF THE DEGREE OF HEAT UP
THERE. SOME OF THE STORMS COULD BE STRONG AND PULSE SEVERE IS
POSSIBLE. A 300 MB JET WILL BE NOSING EASTWARD INTO THE NORTHERN
GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY WHICH MAY INCREASE
THE COVERAGE AND STRENGTH OF THE STORMS.
AVIATION
(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 820 PM EDT MON JUL 15 2019
I EXPECT SOLID VFR CONDITIONS THROUGH THE NIGHT. HOWEVER AFTER
NEARLY A WEEK WITH LITTLE IN THE WAY OF LOWER CIGS/VSBY THE
REMNANTS OF T.D. BARRY WILL MOVE INTO OUR AREA TUESDAY. CURRENTLY
THERE IS AN AREA OF MVFR/IFR CIGS OVER MO AND E IL ASSOICATED
WITH THIS SYSTEM. IT WILL MOVE NORTHEAST INTO LOWER MICHIGAN BY
MID MORNING AND SHOULD REMAIN IN PLACE INTO THE AFTERNOON. I AM
NOT SURE AT THIS POINT HOW FAR NORTH THE RAIN SHIELD WILL GET.
EVEN SO, I DO BELIEVE THE I-94 TAFS WILL BE SOLIDLY IN THE RAIN
TOMORROW. THING IS THERE IS CONSIDERABLE INSTABILITY EVEN WITH
ALL THE LOW CLOUDS AND PRECIPITATION. IT WOULD SEEM THUNDERSTORMS
ARE POSSIBLE WITH THIS SYSTEM TOO. THE SPC SREF HAS A 30 PCT
CHANCE OF THUNDERSTORM AT 21Z NEAR I-94 TUESDAY. SO I HAVE VCTS IN
THE I-94 TAFS TOMORROW AFTERNOON. I HAVE CONDITIONS IMPROVING BY
21Z BUT I AM NOT SURE THAT WILL REALLY BE TRUE. ONE WAY OR THE
OTHER WE WILL HAVE TO MONITOR THIS CLOSELY.
MARINE
ISSUED AT 318 PM EDT MON JUL 15 2019
SOUTH TO SOUTHWEST WINDS COULD BE GUSTY UP AROUND LITTLE AND BIG
SABLE POINTS THIS EVENING INTO TONIGHT. CLOSE CALL FOR A SMALL
CRAFT ADVISORY. THE SOUTHWESTERLY FLOW GENERALLY PERSISTS INTO THE
END OF THE WEEK...BUT LIKELY JUST UNDER CRITERIA. WAVES UP TO 2 TO
4 FEET ARE FORECASTED.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LM...NONE.
UPDATE...WDM
SYNOPSIS...WDM
DISCUSSION...MJS
AVIATION...WDM
MARINE...MJS
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