000
FXUS63 KGRR 240001
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
701 PM EST FRI JAN 23 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 327 PM EST FRI JAN 23 2015

GENERALLY FAIR WEATHER IS EXPECTED UNTIL SUNDAY WHEN A CLIPPER
WILL BRING SOME LIGHT SNOW SOUTH OF INTERSTATE 96. IT WILL TURN
COLD FOR MONDAY AND TUESDAY WITH MODERATING TEMPERATURES FOR
WEDNESDAY AND THURSDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 327 PM EST FRI JAN 23 2015

TWO FORECAST ISSUES IN THE NEAR TERM. ONE IS FOR LIGHT PRECIP
TONIGHT AND THE OTHER IS THE CLIPPER ON SUNDAY. FOR TONIGHT THERE
WILL BE SOME LIGHT SNOW IN THE NORTHERN FORECAST ZONES AS AN AREA
OF CONVERGENCE ALONG A SFC TROUGH SINKS SOUTH ACROSS NORTHERN
LOWER MICHIGAN. PRECIP TYPE SHOULD BE SNOW THROUGH 06Z AND THEN
THE DGZ DRIES OUT AND THERE COULD BE PATCHY FREEZING DRIZZLE
BETWEEN 06Z AND 12Z. THERE IS NOT MUCH LIFT IN THE LOW STRATUS
DECK DURING THAT TIME SO ANY PRECIP SHOULD BE TOO LIGHT TO CAUSE
ANY PROBLEMS.

SATURDAY SHOULD SEE DEEPER MOISTURE MOVE BACK IN AFTER 12Z AND A
PERIOD OF FLURRIES OR LIGHT SNOW IS POSSIBLE BUT AGAIN SHOULD NOT
AMOUNT TO MUCH. THE CLIPPER APPROACHES LATE SATURDAY NIGHT WITH
LIGHT SNOW ACROSS THE SOUTHWEST FORECAST AREA. THERE HAS BEEN A
DEFINITE TREND SOUTHWARD...AND THIS WAS FOLLOWED IN THE FORECAST
BUT LEFT QPF A BIT HIGHER THAN THE 12Z GUIDANCE IN CASE THE PATH
JOGS BACK NORTH TONIGHT. WILL HAVE 1 TO 3 INCHES OF SNOW ACROSS
THE SOUTHERN HALF OF THE FORECAST AREA WITH THE HIGHER AMOUNTS TO
THE SOUTH. MIDNIGHT SHIFT WILL HAVE TO LOWER AMOUNTS IF THE
CURRENT MODEL TRENDS CONTINUE.

ALSO CUT BACK CLOUDS AND LOWERED TEMPERATURES SUNDAY NIGHT AS COLD
AND DRY NORTHEAST FLOW DEVELOPS WITH SFC HIGH BUILDING IN FROM THE
NORTH.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 327 PM EST FRI JAN 23 2015

OVERALL THE LONG TERM PERIOD WILL BE ON THE QUIET SIDE. THE FIRST
CHANCE AT PCPN LOOKS TO BE MONDAY NIGHT AND TUESDAY MORNING AS A
WEAKENING CLIPPER MOVES SOUTH ACROSS WISCONSIN. LIGHT SNOW WILL BE
POSSIBLE OVER THE WESTERN CWA WITH THIS. UPPER RIDGE NOSING INTO THE
GREAT LAKES WILL RESULT IN DRY WX TUESDAY NIGHT-WED AFTER WHICH A
STRONGER CLIPPER WILL MOVE TOWARD THE CWA WEDNESDAY NIGHT AND
THURSDAY.

TEMPS WILL BE COLD MONDAY AND TUESDAY IN THE WAKE OF THE SUNDAY
CLIPPER. HIGHS WILL ONLY MANAGE TO REACH THE LOWER 20S. DITTO FOR
FRIDAY AFTER THE THURSDAY CLIPPER.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 700 PM EST FRI JAN 23 2015

MVFR CONDITIONS LOOK LIKE THEY WILL PERSIST MOST OF IF NOT ALL OF
THE NEXT 24 HOURS. WIDESPREAD MVFR IS IN PLACE ACROSS THE AREA AT
00Z...ALTHOUGH THE EDGES (WHERE VFR CONDITIONS EXIST) ARE CLOSE TO
THE EAST AND WEST.

GIVEN CLIMATOLOGY AND COMPUTER MODEL OUTPUT BOTH WITH A HEAVY LEAN
TOWARDS THE CLOUDS LINGERING KEPT THEM IN THE ENTIRE 24 HOUR TAF
PERIOD. THINKING CEILINGS WILL HOLD IN THE 1000-2000FT RANGE
THROUGH THE PERIOD. THERE ARE EVEN INDICATIONS THAT CEILINGS COULD
DIP TO IFR LEVELS...BUT NOT CONFIDENT ENOUGH TO INCLUDE THAT AT
THIS POINT. HAVE SOME LIGHT FOG IN OVERNIGHT INTO SATURDAY MORNING
(3-5SM). SOME FLURRIES OR EVEN FREEZING DRIZZLE ARE A POSSIBILITY
TONIGHT...BUT CHANCES TOO SMALL TO INCLUDE IN THE TAFS. THINKING
MUCH OF THE ACTIVITY TO THE NORTH ACROSS CENTRAL AND NORTHERN
LOWER MICHIGAN WILL ERODE AS IT MOVES TOWARDS THE TAF SITES.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST FRI JAN 23 2015

RIVER GAUGES AT MOST SITES SHOW WATER LEVELS FALLING. THE MILDER
TEMPERATURES TODAY AND SATURDAY SHOULD NOT CAUSE ENOUGH SNOW MELT OR
ICE MELT TO BE A CONCERN. SNOW AND COLD TEMPERATURES EARLY NEXT WEEK
SHOULD KEEP THE ICE LOCKED UP. WILL CONTINUE MONITORING FOR ANY ICE
JAMS THAT DEVELOP... BUT SERIOUS ICE JAMS ARE UNLIKELY UNTIL THE
NEXT SIGNIFICANT WARM UP AND RAINFALL.

&&

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

$$

SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...93
AVIATION...DUKE
HYDROLOGY...CAS