000
FXUS63 KGRR 071659
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1200 PM EST FRI MAR 7 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 314 AM EST FRI MAR 7 2014

A COLD FRONT MOVING THROUGH THE UPPER MISSISSIPPI VALLEY WILL BE THE
FOCUS FOR OUR WEATHER TODAY AND SATURDAY. TODAY WILL BE MOSTLY DRY
UNTIL PERHAPS LATE IN THE DAY WHEN THE FRONT BEGINS TO MOVE SOUTH
ACROSS CENTRAL LOWER MICHIGAN. MIXED RAIN AND SNOW WILL BE POSSIBLE
NEAR THE FRONT LATE THIS AFTERNOON WITH MAINLY LIGHT SNOW POSSIBLE
TONIGHT. LIGHT SNOW IS AGAIN POSSIBLE SATURDAY AS AN UPPER TROUGH
PASSES BY THE GREAT LAKES.

TEMPERATURES WILL CLIMB TO NEAR 40 TODAY BUT THEN MOVE BACK INTO THE
30S SATURDAY AND SUNDAY.

&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 314 AM EST FRI MAR 7 2014

FORECAST CONCERNS DEAL WITH PCPN NEAR THE FRONT TODAY AND TONIGHT.

WE/VE BEEN WATCHING LIGHT PCPN ON RADAR TAKE IT/S GOOD OLE TIME
MOVING ACROSS MINNESOTA AND NORTHWEST WISCONSIN EARLY THIS MORNING
AHEAD OF A WEAK COLD FRONT. MAIN CHANGE TO THE FORECAST THIS MORNING
WAS TO REMOVE THE MENTION OF JUST RAIN IN THE GRIDS THIS AFTERNOON.
WHILE TEMPERATURES WILL CLIMB INTO THE UPPER 30S TODAY ACROSS MUCH
OF THE CWA...THE PCPN NEAR THE COLD FRONT WON/T ARRIVE UNTIL LATE IN
THE DAY. FORECAST SOUNDINGS SHOW QUITE A BIT OF DRY AIR IN THE LOWER
TROP TODAY AND THAT WILL HAVE TO BE OVERCOME BEFORE PCPN BEGINS.
DYNAMIC COOLING WILL ALSO PULL THE PCPN BACK FROM JUST RAIN TO MORE
OF A MIX OF RAIN AND SNOW LATER THIS AFTERNOON...AND THEN LIGHT SNOW
TONIGHT AS TEMPS COOL INTO THE LOWER 30S. NONE OF THIS PCPN LOOKS
VERY HEAVY AND ANY SNOWFALL ACCUMS SHOULD BE LESS THAN AN INCH.

THE TRAILING UPPER TROUGH WILL MOVE ACROSS THE GREAT LAKES SATURDAY.
WE/LL KEEP THE LOW CHC POPS GOING FOR THIS FEATURE AND THEN BACK TO
DRY WEATHER SUNDAY. TEMPERATURES SATURDAY AND SUNDAY SHOULD TOP OUT
NEAR FREEZING...WHICH IS WAY BELOW NORMAL.

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 AM EST FRI MAR 7 2014

CLEARLY NO LARGE SCALE MAJOR WARMS ARE IN THE PICTURE THROUGH THIS
COMING WEEK. ALSO AT THIS POINT IT WOULD SEEM A QUIET WEATHER
PATTERN SEEMS MORE LIKELY THAN AN ACTIVE ONE THIS COMING WEEK.
HOWEVER... WE WILL HAVE TO WATCH THE SYSTEM FOR TUESDAY NIGHT INTO
WEDNESDAY AS IT COULD BRING SIGNIFICANT SNOW TO THE AREA IF IT WOULD
TRACK A TOUCH FARTHER NORTH THAN THE MODELS ARE CURRENTLY SUGGESTING.

THERE IS SOME SUGGESTION FROM THE ECMWF (MORE SO THAN FROM THE GFS)
THAT THE PHASING OF A SOUTHERN STREAM WAVE AND A NORTHERN STREAM
WAVE IN THE TUESDAY NIGHT TO WEDNESDAY TIME FRAME COULD BRING
SIGNIFICANT PRECIPITATION TO AT LEAST OUR SOUTHERN CWA IF THE SYSTEM
WAS A TOUCH DEEPER. NEITHER THE OPERATION GFS OR CANADIAN SEEM TO
LIKE THIS IDEA. EVEN SO IT SHOULD BE POINTED OUT THAT THE GFS
ENSEMBLES ARE SHOWING A BETTER ORGANIZED...DEEPER SURFACE LOW THAN
DOES THE OPERATION GFS SO THE AREA OF SIGNIFICANT PRECIPITATION
SHOWN FOR THAT IS AS FAR NORTH AS HTL BY WEDNESDAY MORNING. WE WILL
HAVE TO WATCH THIS AS IT COULD BE SIGNIFICANT PRECIPITATION EVENT IF
IT DOES GET FARTHER NORTH.

OTHER THAN THAT...A NORTHER STREAMS SYSTEM PASSES NORTH OF THE AREA
MONDAY BRINGING A SURGE OF WARM AIR TO THE REGION (NOT ALL THAT WARM
/ NEAR NORMAL IS AS GOOD AS SHOULD DO MONDAY). IT SEEMS TO DRY FOR
MUCH PRECIPITATION FROM THIS BUT HIGHS IN THE LOWER 40S SEEM LIKELY
AS WE GET INTO THE WARM SECTOR OF THIS SYSTEM.  THE COLD FRONT
TRAILING THE SYSTEM COULD BRING SPRINKLES OR FLURRIES MONDAY NIGHT
OR TUESDAY BUT NOTHING SIGNIFICANT HERE EITHER. BEYOND THAT COLD AIR
RETURNS FOR WEDNESDAY INTO FRIDAY. THAT HAPPENS WHETHER WE GET THE
STORM TUESDAY NIGHT INTO WEDNESDAY OR NOT.

LOOKING AT THE LARGER SCALE... WE FIND OUR POLAR VORTEX NEAR THE
NORTH POLE (NO SURPRISED THERE)... HOWEVER THE ASSOCIATED LARGE
SCALE UPPER TROUGH SEEMS TO WANT TO REMAIN GLUED TO EASTERN NORTH
AMERICA FOR THE FORESEEABLE FUTURE. A QUICK LOOK AT THE FORECAST
HEIGHTS FOR THE STRATOSPHERE (30-70 MB) OVER NORTH AMERICA INTO NEXT
WEEKEND CLEARLY SHOW THE EASTERN TROUGH REMAINING IN PLACE. WATCHING
THESE FORECAST FROM DECEMBER THROUGH EARLY FEBRUARY (I WAS ON
VACATION LATER IN FEBRUARY) SEEM TO SHOW A DECENT AMOUNT OF SKILL
FOR THE LARGE SCALE FEATURES.

THAT BEING SO OUR TEMPERATURES SHOULD OVERALL REMAIN COLDER THAN
NORMAL FOR SOME TIME TO COME. A MORE SOUTHERN STORM TRACK SHOULD BE
EXPECTED INTO NEXT WEEK. THE CPC 6 TO 10 DAY AND 8 TO 14 DAY
FORECAST CONFIRM THIS IDEA AS DO THE CPC 500 MB HEIGHT ANALOGS. THE
HPC 7 DAY TOTAL PRECIPITATION FORECAST SHOWS FROM 1 TO 3 INCHES OF
PRECIPITATION FROM OHIO SOUTH AND EAST TO THE GULF COAST THROUGH
FRIDAY MARCH 14TH. OVER MICHIGAN IT SHOWS AROUND A HALF INCH OF
QPF.

BOTTOM LINE WE NEED TO WATCH WHAT HAPPENS TUESDAY INTO WEDNESDAY
WITH THAT SOUTHERN STREAM STORM OTHERWISE A SLOW SNOW MELT IS OUR
STORY THROUGH NEXT WEEK (MARCH 14TH).

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY)
ISSUED AT 1200 PM EST FRI MAR 7 2014

VFR CONDITIONS ARE ANTICIPATED AT ALL THE TERMINALS THIS AFTERNOON
AND EARLY EVENING. HOWEVER CONDITIONS WILL LIKELY DETERIORATE TO
MAINLY MVFR LATE THIS EVENING AND OVERNIGHT AS SOME PATCHY FOG
DEVELOPS DUE TO LOTS OF LOW LEVEL MOISTURE FROM SNOW MELT TODAY.

IN ADDITION A WEAK FRONTAL SYSTEM WILL BRING LOW CLOUDS LATE TONIGHT
ALONG WITH POTENTIAL FOR A FEW LIGHT SNOW SHOWERS AND FLURRIES.
CANNOT RULE OUT A LITTLE LIGHT MIXED PCPN BUT LIGHT SNOW
SHOWERS/FLURRIES ARE THE MOST LIKELY PCPN TYPE.

LOW CLOUDS WILL LINGER BEHIND THE SYSTEM CAUSING CONDITIONS TO
REMAIN MAINLY MVFR THROUGH 18Z SATURDAY. SOME PATCHY IFR CONDITIONS
ARE ALSO POSSIBLE LATE TONIGHT THROUGH MIDDAY SATURDAY DUE TO THE
COMBINATION OF LOW CLOUDS/FOG/LIGHT PCPN.

&&

.HYDROLOGY...
ISSUED AT 326 PM EST THU MAR 6 2014

WITH MAX TEMPS AROUND 40 FRIDAY...AND IN THE LOW TO MID 30S
SATURDAY...WE WILL SEE SOME GRADUAL SNOW MELT.  CURRENT SNOW WATER
EQUIVALENT VALUES ARE GENERALLY IN THE 2 TO 5 INCH RANGE AND LARGELY
REMAIN UNCHANGED IN RECENT DAYS. WITHOUT MUCH RAIN IN THE FORECAST
AND NEAR TO SLIGHTLY BELOW NORMAL TEMPS...STABLE RIVER CONDITIONS
ARE EXPECTED INTO EARLY NEXT WEEK. SOME LOSS OF SWE IS LIKELY
THROUGH NEXT WEEK.

&&

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

$$

SYNOPSIS...93
SHORT TERM...93
LONG TERM...WDM
AVIATION...LAURENS
HYDROLOGY...JK