Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 211148
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
748 AM EDT MON JUL 21 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 325 AM EDT MON JUL 21 2014

A RIDGE OF HIGH PRESSURE WILL CONTINUE TO BRING FAIR WEATHER
TODAY AND TUESDAY AND IT WILL BECOME QUITE WARM AND INCREASINGLY
HUMID THROUGH TUESDAY AFTERNOON. A COLD FRONT WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY MORNING.
FAIR AND COOLER WEATHER IS EXPECTED FOR MID TO LATE WEEK.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 325 AM EDT MON JUL 21 2014

OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
CONVECTIVE/SEVERE POTENTIAL FOR TUESDAY NIGHT.

A CONSENSUS OF LATEST SHORT RANGE GUIDANCE CONTINUES TO LOOK
UNFAVORABLE FOR SEVERE WX TUESDAY NIGHT GIVEN WEAK DEEP LAYER
SHEAR... THE FRONTAL TIMING AND DIMINISHING INSTABILITY OVERNIGHT.
SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND JUST
AHEAD OF THE FRONT TUESDAY NIGHT BUT SEVERE WX IS UNLIKELY.

FAIR AND INCREASINGLY WARM AND HUMID WX IS ANTICIPATED TODAY
THROUGH TUESDAY AFTERNOON. MAX TEMPS TODAY WILL REACH THE MIDDLE 80S
AND HIGH TEMPS MONDAY AND TUESDAY WILL RANGE FROM THE MIDDLE 80S
TO NEAR 90 DEGREES ALONG WITH INCREASING HUMIDITY AS DEW POINT VALUES
CLIMB THROUGH THE 60S. THERE IS JUST A SMALL CHC OF A SHOWER OR STORM
OVER OUR NW FCST AREA NW OF KGRR TUESDAY AFTERNOON BUT THE BETTER
CHANCE FOR PCPN WILL HOLD OFF UNTIL TUESDAY NIGHT.

AFTER A FEW LINGERING SHOWERS AND PERHAPS A STORM WEDNESDAY MORNING
A MUCH COOLER AND LESS HUMID AIRMASS WILL ADVECT IN FOR THE REST
OF THE DAY WEDNESDAY.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM EDT MON JUL 21 2014

THE END OF THIS WEEK LOOKS QUIET/COMFORTABLE AS A LARGE CANADIAN SFC
HIGH IMPACTS THE REGION. DEW POINTS WILL BE IN THE 50S WITH PLENTY
OF SUNSHINE BOTH THURSDAY AND FRIDAY.

IT MAY TURN A BIT UNSETTLED FOR NEXT WEEKEND ALTHOUGH CERTAINLY NOT
A WASHOUT. ZONAL FLOW ALOFT SHOULD DRIVE A FEW FAST MOVING
SHORTWAVES THROUGH THE REGION ALTHOUGH BEST MOISTURE/INSTABILITY
ASSOCIATED WITH THE SFC WARM FRONT IS PROGGED TO REMAIN SOUTH OF
MICHIGAN. IF THAT PATTERN HOLDS... THE BEST TSTM/MCS CHANCES NEXT
WEEKEND SHOULD BE ACROSS IOWA/MISSOURI/ILLINOIS/INDIANA... WITH OUR
WEATHER PROBABLY FEATURING PERIODS OF THICKER MID LEVEL CLOUDS AND
SCATTERED RAIN SHOWERS OCCURRING NORTH OF THAT MCS ACTIVITY. TEMPS
SHOULD BE NEAR OR A BIT BELOW NORMAL SINCE THE WARM FRONT DOES NOT
MAKE IT THIS FAR NORTH.

LOOKING EVEN FARTHER AHEAD TO THE WEEK OF 7/28... CONFIDENCE IS
ALREADY RELATIVELY HIGH FOR A LENGTHY PERIOD OF BELOW NORMAL
TEMPERATURES AS ANOTHER LONGWAVE TROUGH SETS UP OVER THE EASTERN
HALF OF THE NATION. GFS/ECMWF IN GOOD AGREEMENT ON THIS SCENARIO.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 747 AM EDT MON JUL 21 2014

LIGHT MVFR FOG WILL LIFT LATER THIS MORNING... FOLLOWED BY VFR
CONDITIONS THIS AFTERNOON AND TONIGHT. SOME LIGHT FOG/HAZE WILL
PROBABLY FORM AGAIN VERY LATE TONIGHT/EARLY TUESDAY...AFTER 10Z.

&&

.MARINE...
ISSUED AT 325 AM EDT MON JUL 21 2014

SW WINDS OF 10 TO 15 KTS WILL PRODUCE WAVE HEIGHTS MAINLY IN THE
1 TO 3 FOOT RANGE TODAY AND TONIGHT. HIGHEST WAVE HEIGHTS WILL BE
FOUND NORTH OF MUSKEGON. STRONGER SSW WINDS OF 15 TO 25 KTS TUESDAY
WILL CAUSE WAVE HEIGHTS TO BUILD TO 2 TO 4 FEET WITH HIGHEST WAVES
AGAIN NORTH OF MUSKEGON. A SMALL CRAFT ADVISORY WILL LIKELY
EVENTUALLY BE NEEDED FOR TUESDAY NIGHT AND WEDNESDAY.


&&

.HYDROLOGY...
ISSUED AT 314 PM EDT SUN JUL 20 2014

QPF FOR TUESDAY NIGHT AND WEDNESDAY WILL NOT BE ENOUGH TO CAUSE ANY
SIGNIFICANT RESPONSE ON MAIN STEM RIVERS AND LITTLE RESPONSE IS
EXPECTED ON SMALL RIVERS AND STREAMS. THEREFORE...WE DO NOT
ANTICIPATE FLOODING CONCERNS THIS WEEK. MAPLE RAPIDS HAS FALLEN
BELOW BANKFULL AND WILL CONTINUE DROPPING. OTHER RIVERS ARE RUNNING
NEAR TO ABOVE NORMAL BUT WELL WITHIN BANKS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...HOVING
MARINE...LAURENS







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