000
FXUS63 KGRR 100404
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1204 AM EDT MON MAR 10 2014

LATEST UPDATE...
AVIATION

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

A WEAK AREA OF LOW PRESSURE WILL TRACK EASTWARD THROUGH ONTARIO
AND QUEBEC THROUGH MONDAY. SOUTHWEST WINDS AHEAD OF THIS SYSTEM
WILL DRAW UP SOME MILDER AIR FROM THE CENTRAL PLAINS INTO MICHIGAN.
A SECOND LOW PRESSURE SYSTEM WILL TRACK UP THE OHIO VALLEY TUESDAY
INTO WEDNESDAY LEADING TO UNSETTLED WEATHER HERE IN LOWER
MICHIGAN. A MUCH COLDER AIRMASS WILL FILTER IN BEHIND THIS SYSTEM.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 318 PM EDT SUN MAR 9 2014

THE MAIN CHALLENGE DEALS WITH THE TEMPERATURES ON MONDAY AND
AMOUNT OF SNOW TUESDAY NIGHT.

GUIDANCE IS QUITE LOW WITH TEMPERATURES ON MONDAY...AND THERE IS A
FAIRLY STRONG SIGNAL FOR LOW CLOUDS TO FORM. FSL RUC AND HRRR RUC
ARE SHOWING THESE LOW CLOUDS FORMING. IF THEY DO FORM AND HOLD
THROUGH THE DAY...GUIDANCE WILL LIKELY END UP CORRECT IN SHOWING
HIGHS GENERALLY IN THE LOW 40S. HOWEVER LIKE TODAY...THE LOW
CLOUDS DID BREAK UP AND THAT COULD HAPPEN TOMORROW. STRONGER
SOUTHWEST FLOW SHOULD HELP THIS TO HAPPEN. SO I WILL MAINTAIN THE
MILD LOW 50 DEGREE TEMPERATURES.

LOOKS LIKE POTENTIAL FOR PRECIPITATION ON TUESDAY IS FAIRLY LOW AS
THE LIFT LOOKS WEAK AND THERE IS SOME DRY AIR BELOW THE MOIST DGZ.
I WILL KEEP THE POPS AT LOW LEVELS. TUESDAY NIGHT HOWEVER...THE
LOW TRACKING UP THE OH VALLEY WILL LIKELY SPREAD SNOW INTO
SOUTHERN LOWER MI. SOME DECENT MID LEVEL FGEN AND DIVERGENCE IN
THE UPPER LEVELS SUPPORT THIS SCENARIO. THERE IS ALSO SOME
WEAKNESS IN THE STABILITY SHOWING UP AROUND THE DGZ...WHICH COULD
SUPPORT A STRONGER BAND OF SNOW. WILL NEED TO MONITOR TRENDS ON
THIS. I WILL MAINTAIN SEVERAL INCHES OF SNOW FOR THE I94 CORRIDOR.
SOUNDINGS SUPPORT SNOW AFTER 00Z WED.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 318 PM EDT SUN MAR 9 2014

THE MODEL TRENDS CONTINUE TO SHOW A STRONGER SURFACE LOW OVER THE OH
VALLEY FOR WED.  WITH A STRONGER SYSTEM...THE DEFORMATION ZONE IS
LIABLE TO BE FURTHER NORTH AND THERE IS INCREASING CONFIDENCE THE
STEADIER SNOWS WITH THIS SYSTEM WILL CLIP AT LEAST THE FAR SE CWA.
SNOW ACCUMS IN CALHOUN AND JACKSON COUNTIES COULD REACH TOWARD SIX
INCHES BY WED EVENING.  IT APPEARS THERE SHOULD BE A SHARP CUT OFF
TO THE SNOW TO THE NORTH...ESPECIALLY NORTH OF I-96.  THIS CONTINUES
TO BE AN EVOLVING SOLUTION AS THE NORTH AND SOUTHERN STREAM ENERGY
THAT PRODUCE THIS SYSTEM WAS JUST MAKING IT ONTO THE WESTERN U.S.
COAST TODAY...AND THE SOLUTION IS SUBJECT TO CHANGE.

THE OTHER IMPRESSIVE ASPECT OF THIS SYSTEM IS THE COLD AIR THAT
FOLLOWS IT.  H8 TEMPS DIVE TO AROUND -17C...WHICH HAS TRENDED
COLDER.  THIS WILL PROBABLY RESULT IN STEADY OR FALLING TEMPS ON
WED...INTO THE TEENS BY EVENING.  THE SYSTEM LIFTS OUT QUICKLY WED
NIGHT AND WITH CLEARING SKIES...MINS SHOULD DROP TO AROUND ZERO.
THIS WOULD POTENTIALLY BE RECORD LEVELS.  CURRENT RECORDS FOR 03/13
ARE 5F AT GRR...2F AT MKG...AND -3F AT LAN.

THE REST OF THE WEEK SHOULD SEE TEMPS RETURN TO NEAR NORMAL...BUT
THEN TURNING COOLER AGAIN DURING NEXT WEEKEND.  NO SIGNIFICANT
SYSTEMS APPEAR TO IMPACT SW MI...ALTHOUGH A SOUTHERN STREAM SYSTEM
IS SHOWN OVER THE TN VALLEY BY SUNDAY WHICH COULD BRING LIGHT SNOW
TO THE SOUTHERN CWA.

&&

.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...MJS
SHORT TERM...MJS
LONG TERM...MJS
AVIATION...MEADE
HYDROLOGY...MJS