000
FXUS63 KGRR 100718
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
318 AM EDT MON MAR 10 2014

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 318 AM EDT MON MAR 10 2014

THE AREA IS EXPECTED TO SEE ONE OF THE NICEST DAYS TODAY SINCE MID
NOVEMBER. TEMPERATURES HAVE A GOOD CHANCE OF HITTING 50 DEGREES
ALONG WITH SEEING A GOOD DEAL OF SUNSHINE. THE MILD AND QUIET
WEATHER IS EXPECTED TO CONTINUE INTO EARLY TUESDAY.

COLDER AIR WILL START MOVING IN ACROSS THE AREA LATER TONIGHT AND
DURING THE DAY ON TUESDAY. SOME LIGHT RAIN AND/OR SNOW WILL BE
POSSIBLE TUESDAY AFTERNOON. ALL PRECIPITATION WILL CHANGE OVER TO
SNOW TUESDAY EVENING...AND A FEW INCHES OF SNOW WILL BE POSSIBLE
TOWARD SOUTHEAST LOWER MICHIGAN. MUCH COLDER AIR WILL THEN BE IN
PLACE ON WEDNESDAY AND THURSDAY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 318 AM EDT MON MAR 10 2014

MAIN ISSUES IN THE SHORT TERM CONTINUE TO BE MAX TEMPS FOR TODAY AND
THEN SNOWFALL POTENTIAL FOR TUE NIGHT AND WED. WE ARE NOT REALLY
MAKING ANY CHANGES TO ANYTHING.  WE ALSO BELIEVE THAT SOME
ACCUMULATIONS OF SNOW WILL BE LIKELY ACROSS THE FAR SOUTH TUE NIGHT
AND WED.

WE CONTINUE TO BELIEVE AT LEAST A FEW AREAS WILL HIT 50 TODAY...IF
NOT ENDING UP A BIT WARMER. THE UNCERTAINTY IN HOW WARM WE GET TODAY
CONTINUES TO BE IN THE POTENTIAL OF POSSIBLE STRATUS DEVELOPMENT
THIS MORNING. THE NAM AND GFS CONTINUE TO INDICATE A GOOD DEAL OF
MOISTURE EXPECTED TO DEVELOP BELOW 1K FEET. THIS SHOULD BE STARTING
TO OCCUR ALREADY...HOWEVER THERE ARE NO REAL SIGNS YET.

WE BELIEVE THERE COULD BE SOME PATCHY LOW CLOUD DEVELOPMENT LIKE
YESTERDAY MORNING...ESPECIALLY AFTER WINDS DROP OFF A LITTLE MORE IN
AROUND 09Z OR SO. WE DO BELIEVE THAT THE MODELS BIAS OF TOO MUCH
MOISTURE IN THE BOUNDARY LAYER IS A FACTOR TODAY. THERE IS A DECENT
GRADIENT THAT REDEVELOPS THIS AFTERNOON WHICH SHOULD HELP MIX ANY
LOW CLOUD COVER OUT. MID AND HIGH CLOUDS FROM THIS MORNING ARE
EXPECTED TO MOVE OUT ALSO. WITH A CYCLONIC LOW LEVEL FLOW AHEAD OF
THE INCOMING SYSTEM TO OUR NORTH...THIS SHOULD ENHANCE THE MIXING.
H850 TEMPS OF AROUND 8C SUPPORT HIGHS EASILY IN THE 50S WITHOUT LOW
CLOUD ISSUES. WE WILL CONTINUE TO REMAIN SLIGHTLY CONSERVATIVE...
BUT FCST HIGHER THAN THE MOS VALUES OF AROUND 40.

WE WILL SEE COOLER AIR BEGIN TO MOVE IN TONIGHT AS A FRONTAL SYSTEM
DROPS SOUTH THROUGH THE AREA. WE CONTINUE TO EXPECT THAT THIS FRONT
WILL MOVE THROUGH DRY AS THERE IS REALLY NO MOISTURE TO SPEAK OF
BELOW 7K FEET THROUGH TONIGHT.

WHAT WILL HAPPEN HOWEVER IS WE WILL SEE LIGHT PCPN START TO DEVELOP
NORTH OF THE FRONT DURING THE DAY ON TUE...ESPECIALLY DURING THE
AFTERNOON HOURS ACROSS OUR AREA. A SHORT WAVE AND ASSOCIATED SFC LOW
WILL COME OUT OF THE CENTRAL PLAINS. ISENTROPIC ASCENT AHEAD OF THIS
WAVE WILL OVERRUN THE SFC FRONT AND LEAD TO THE DEVELOPMENT OF PCPN.
IT WILL REMAIN LIGHT AND COULD BE RAIN PER WET BULB ZERO HTS IF AT
ALL ON TUE AFTERNOON AS LOW LEVEL MOISTURE WILL REMAIN LIMITED WITH
A DRY NNE FLOW. PCPN WILL BECOME MORE ORGANIZED TUE EVENING AS A
STRONGER NRN STREAM WAVE DIVES SE OUT OF CANADA AND RAMPS UP THE MID
LEVEL FGEN FORCING AS IT BEGINS TO PHASE WITH THE SRN STREAM SYSTEM.

THE PCPN WILL BECOME MUCH MORE ORGANIZED OVERNIGHT TUE NIGHT AND WED
MORNING. THE PLACEMENT OF THE HEAVIER SNOW WILL BE DEPENDENT ON THE
EXACT TIMING OF THE PHASING OF THE SYSTEMS. THE THEME HAS BEEN THAT
THE PHASING WILL MAXIMIZE AFTER THE NRN TROUGH IS FURTHER SOUTH SO
THAT THIS WILL NOT BE A BIG ISSUE FOR MOST OF MICHIGAN. WE CONTINUE
TO BELIEVE THIS THINKING. THIS IS NOT SET IN STONE BY ANY MEANS
HOWEVER AS THE TWO MAIN PLAYERS ARE CURRENTLY JUST OFFSHORE OF THE
WRN U.S. COAST AND UP ACROSS AK. SMALL CHANGES IN THE TIMING OF THE
PHASING WILL HAVE POTENTIALLY BIG IMPLICATIONS FOR LESS OR MORE SNOW
ACCUMULATIONS. WE WILL CONTINUE TO MONITOR THE TRENDS WITH THESE
FEATURES.

COLDER TEMPS WITH A CHANCE OF SNOW SHOWERS CAN BE EXPECTED EITHER
WAY FOR WED AS THE NEXT BLAST OF ARCTIC AIR AFFECTS THE AREA.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 AM EDT MON MAR 10 2014

THE EXTENDED PERIOD BEGINS WITH A SHOT AT SOME RECORD COLD
TEMPERATURES WEDNESDAY NIGHT. SFC RIDGING MOVES OVER LOWER MICHIGAN
WITH LIGHT WINDS AND CLEAR SKIES EXPECTED. LOWS COULD PLUNGE TO NEAR
OR BELOW ZERO EVEN ACROSS THE SOUTHERN FORECAST AREA WHERE SOME
FRESH SNOWCOVER WILL HELP THE CAUSE.

TEMPERATURES MODERATE TO NEAR NORMAL BY FRIDAY AS RETURN FLOW SETS
UP AS THE SFC RIDGE MOVES EAST. NO BIG STORMS ARE EXPECTED IN THE
EXTENDED PERIOD. THERE WILL BE A SLIGHT CHANCE OF LIGHT SNOW FRIDAY
NIGHT AS A CLIPPER MOVING ACROSS THE NORTHERN LAKES BRINGS A COLD
FRONT THROUGH. A REINFORCING ARCTIC FRONT COULD PICK UP ENOUGH
MOISTURE TO BRING SOME SNOW SHOWERS ON SUNDAY AS WELL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1159 PM EDT SUN MAR 9 2014

STILL NO EVIDENCE OF ANY LOW CLOUDS FORMING AT MIDNIGHT AND SFC
WINDS ARE STILL HOLDING ABOVE 10 KNOTS. HAVE DECIDED TO BE LESS
AGGRESSIVE WITH MVFR CIGS IN THE TAFS LATE TONIGHT AND MONDAY
MORNING BUT WILL KEEP A MENTION OF SOME LIGHT FOG AND SCATTERED
CLOUDS BLO 1000 FT. WINDS ARE EXPECTED TO DIMINISH 09Z-15Z WHICH
WOULD OFFER A BETTER OPPORTUNITY OF THIS OCCURRING.

OTHERWISE... OUTSIDE OF ANY STRATUS/FOG ISSUES WHICH IS LOW
CONFIDENCE... LOOK FOR VFR CONDITIONS CONTINUING OVERNIGHT AND
MONDAY. SOUTHWEST WIND WILL PICK UP AGAIN MONDAY AFTERNOON WITH
SOME GUSTS TO 20-25KT POSSIBLE THROUGH 00Z.


&&

.HYDROLOGY...
ISSUED AT 318 PM EDT SUN MAR 9 2014

NO MAJOR PRECIPITATION SYSTEMS SEEN THROUGH THE FORECAST PERIOD. A
MODERATING TREND IN THE TEMPERATURES IS PREDICTED FOR MONDAY INTO
TUESDAY. THIS WILL LEAD TO GRADUAL MELTING. TEMPERATURES DO COOL
DOWN FOR THE MIDDLE PART OF THE WEEK WHICH WILL SLOWLY DOWN OR
STOP ANY MELTING. TEMPERATURES THEN TRY TO MODERATE FOR THE END OF
THE WEEK. AS A RESULT...THE SNOWPACK WILL ONLY SLOWLY RELEASE SOME
OF ITS WATER THROUGH THE PERIOD. WITH LIMITED RUNOFF WATER LEVELS
SHOULD STAY FAIRLY STABLE THIS WEEK.

&&

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

$$

SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...MEADE
HYDROLOGY...MJS