210  
FXUS63 KGRR 120452  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
1152 PM EST THU FEB 11 2016  
 
LATEST UPDATE...  
AVIATION  
   
SYNOPSIS
 
 
CORRECTED AT 442 PM EST THU FEB 11 2016  
 
SCATTERED LIGHT SNOW SHOWERS ARE EXPECTED OVERNIGHT WITH LITTLE IN  
THE WAY OF ACCUMULATION BUT LOWS WILL BE COLD... MOSTLY BETWEEN 10  
AND 15 ABOVE. AN ARCTIC FRONT COMES THROUGH FRIDAY AND IT WILL  
BRING SNOW SHOWERS AND INCREASED WINDS. MOST AREAS WILL SEE  
MEASURABLE SNOW BY EVENING. AS THE ARCTIC AIR COMES IN FRIDAY  
NIGHT...BRINGING IN THE COLDEST AIR OF THE WINTER... LAKE EFFECT  
SNOW SHOWERS WILL BE HEAVY AT TIMES ALONG THE LAKE SHORE WITH  
AREAS SOUTH OF HOLLAND AND WEST OF US-31 SEEING THE HEAVIEST SNOW  
WITH CONSIDERABLE BLOWING AND DRIFTING SNOW. THE WIND AND SNOW ALONG  
THE LAKE SHORE SUBSIDE BY SATURDAY EVENING BUT TEMPERATURES WILL BE  
VERY COLD WITH HIGHS BETWEEN 10 AND 15 DEGREES.  
 
A SERIES OF WEAK SYSTEMS WILL MOVE THROUGH THE AREA BETWEEN MONDAY  
AND WEDNESDAY BRINGING SOME ADDITIONAL SNOW... BUT TEMPERATURES WILL  
WARM TO NEAR FREEZING.  
 

 
   
UPDATE
 
 
ISSUED AT 928 PM EST THU FEB 11 2016  
 
NO CHANGES TO THE HEADLINES. THE ARCTIC FRONT IS CURRENTLY JUST  
NORTH OF LAKE SUPERIOR AND WILL CONTINUE TO MOVE SOUTH TONIGHT.  
CONVERGENCE AHEAD OF THE FRONT WILL LIKELY RESULT IN SOME SNOW  
FORMATION FRIDAY MORNING WITH MORE SUBSTANTIAL LAKE EFFECT SNOW  
SHOWERS BEHIND THE FRONT.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH SATURDAY NIGHT)  
CORRECTED AT 442 PM EST THU FEB 11 2016  
 
I HAVE ISSUED A WINTER STORM WARNING FOR ALLEGAN AND VAN BUREN  
COUNTIES FROM FRIDAY MORNING THROUGH SATURDAY AFTERNOON WITH OVER A  
FOOT OF SNOW POSSIBLE LOCALLY ACCOMPANIED BY GUSTY WINDS CAUSING  
BLOWING AND DRIFTING SNOW. I HAVE ALSO ISSUED A WINTER WEATHER  
ADVISORY FOR THE REST OF THE LAKE SHORE COUNTIES FOR THE SAME TIME  
PERIOD BUT SNOWFALL THERE WILL BE MORE IN THE 4 TO 8 INCH RANGE.  
FOR THE SECOND ROW OF COUNTIES INLAND... I ISSUED A WINTER WEATHER  
ADVISORY FOR THE SNOW SHOWERS WITH THE ARCTIC FRONT SINCE BOTH THE  
MORNING AND EVENING COMMUTES WILL BE IMPACTED BY IT.  
 
WITH THE SURFACE HIGH MOVING SOUTH OF THE AREA THIS EVENING AND  
THE TROUGH ASSOCIATED WITH THE ARCTIC FRONT STARTING TO DROP  
SOUTHWARD INTO NORTHERN LOWER MICHIGAN... THE LAKE EFFECT SNOW WILL  
MOVE INLAND AND DISSIPATE. HOWEVER SNOW WILL QUICKLY REFORM AS  
SOUTHWEST TO WEST WINDS OVER LAKE MICHIGAN IN COMBINATION WITH THE  
TROUGH MOVING IN CREATE SURFACE CONVERGENCE NEAR I-96. NONE OF THIS  
WILL ACCUMULATE TO MUCH THOUGH. MORE LIKE NUISANCE LIGHT SNOW  
SHOWERS.  
 
ONCE THE ARCTIC FRONT GETS INTO SOUTHWEST MICHIGAN FRIDAY THE  
INVERSION HEIGHTS JUMP TO 8000 FT WHILE THE DGZ INCREASES IN DEPTH  
TO NEARLY 6000 FT. WITH THE LIFT ASSOCIATED WITH THE ARCTIC FRONT...  
THE DEEP MOISTURE AND DEEP DGZ IT WOULD SEEM WE SHOULD SEE A PERIOD  
OF AT LEAST MODERATE SNOW JUST AHEAD OF THE ARCTIC FRONT. HENCE THE  
WINTER WEATHER ADVISORY FOR THE SECOND ROW OF COUNTIES INLAND DURING  
THE DAY TOMORROW.  
 
BEHIND THE ARCTIC FRONT WE HAVE 8000 FT INVERSION HEIGHTS THROUGH A  
GOOD PART OF FRIDAY NIGHT INTO SATURDAY MORNING. THETA-E DECREASES  
WITH HEIGHT TO 8000 FT WHILE THERE IS UP TO 200 J/KG OF CAPE AS THE  
COLDEST AIR OF THE WINTER CROSSES LAKE MICHIGAN ON NORTH NORTHWEST  
WINDS. THIS WILL SET UP A DOMINANT SNOW BAND FROM NEAR SOUTH HAVEN  
TO AROUND BLOOMINGDALE ( MORE OR LESS) THAT WILL REMAIN NEARLY  
STATIONARY A GOOD PART OF THE NIGHT. I EXPECT HEAVY SNOWFALL WITH  
GUSTY WINDS DURING THIS TIME... HENCE THE WARNING.  
 
ALL OF THIS SLOWLY DIMINISHES SATURDAY BUT IT WILL REMAIN COLD.  
   
LONG TERM
 
(SUNDAY THROUGH THURSDAY)  
ISSUED AT 328 PM EST THU FEB 11 2016  
 
HIGH TEMPS WILL REBOUND TO REACH THE UPPER TEENS TO LOWER 20S SUNDAY  
AFTERNOON AFTER A VERY COLD START TO THE DAY WITH TEMPS RANGING FROM  
5 BELOW TO 5 ABOVE ZERO ACROSS MOST OF OUR FCST AREA EARLY SUNDAY  
MORNING WITH HIGH PRESSURE AND CLEARING SKIES SETTING UP EXCELLENT  
RADIATIONAL COOLING CONDITIONS.  
 
SEVERAL WEAK LOW PRESSURE SYSTEMS AND UPPER LEVEL DISTURBANCES WILL  
MOVE THROUGH SUNDAY NIGHT THROUGH THE EARLY TO MIDDLE PORTION OF  
NEXT WEEK BRINGING SEVERAL CHANCES FOR LIGHT SNOW. TEMPS WILL  
MODERATE AND RETURN TO NEAR NORMAL FOR THIS TIME OF YEAR FOR MOST OF  
NEXT WEEK.  
 
IT IS NOTED THAT THE 12Z ECMWF DEVELOPS A MORE SIGNIFICANT LOW  
PRESSURE SYSTEM ALONG THE GULF COAST REGION MONDAY AND TAKES IT  
NORTHEAST TO THE MID ATLANTIC REGION WHILE ALSO INDICATE THIS SYSTEM  
COULD STRENGTHEN. A CONSENSUS OF LATEST MEDIUM RANGE GUIDANCE  
INCLUDING THE GLOBAL GEM... UKMET AND GFS ALL CONTINUE TO SUGGEST  
THAT THIS SYSTEM SHOULD STAY WELL SE OF OUR REGION.  
 
HOWEVER IF THE UPPER LEVEL TROUGH OVER THE EASTERN GREAT LAKES  
REGION EARLY NEXT WEEK DEEPENS WITH PHASING OF THE NORTHERN AND  
SOUTHERN STREAMS THEN THERE WOULD BE POTENTIAL FOR THAT  
STRENGTHENING SYSTEM TO IMPACT LWR MI. SO WE WILL NEED TO MONITOR  
THE EVOLUTION OF THAT SYSTEM AND MEDIUM RANGE GUIDANCE TRENDS  
CLOSELY AS 12Z OPERATIONAL ECMWF GUIDANCE INDICATES THAT THIS SYSTEM  
COULD POTENTIALLY IMPACT FAR SOUTH TO SE LWR MI MONDAY  
NIGHT/TUESDAY.  
 
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)  
ISSUED AT 1152 PM EST THU FEB 11 2016  
 
VFR WEATHER IS EXPECTED OVERNIGHT WITH PREDOMINANTLY MVFR AFTER  
12Z FRIDAY. SNOW SHOWERS WILL FLARE UP ONCE AGAIN FRIDAY MORNING  
AS AN ARCTIC FRONT DROPS SOUTH THROUGH LOWER MICHIGAN. SPOTTY IFR  
IS NOT OUT OF THE QUESTION IN HEAVIER SNOW. THE EASTERN TAF  
SITES...LAN...JXN...AND BTL SHOULD BE ABLE TO IMPROVE TO VFR  
FRIDAY EVENING AS THE SNOW TRANSITIONS TO A NORTH NORTHWEST FLOW  
LAKE EFFECT SCENARIO. MVFR WILL LINGER AT MKG.  
 
WESTERLY WINDS WILL INCREASE TO 10-15 KTS THROUGH LATE MORNING  
INTO THE AFTERNOON. GUSTS TO 25 KTS WILL BE POSSIBLE DURING THE  
AFTERNOON AND EVENING AS WINDS GO NORTHWEST.  
 

 
   
MARINE
 
 
ISSUED AT 203 PM EST THU FEB 11 2016  
 
A SMALL CRAFT ADVISORY CONTINUES IN EFFECT THROUGH 1 PM FRIDAY AND  
IS FOLLOWED BY A GALE WATCH FOR FRIDAY AFTERNOON THROUGH SATURDAY  
MORNING. WAVE HEIGHTS WILL GRADUALLY BUILD PARTICULARLY ON FRIDAY  
DUE TO STRONG NORTHWEST WINDS THAT COULD POTENTIALLY REACH GALE  
FORCE AND THE COLD AIR ADVECTION. FREEZING SPRAY WILL ALSO DEVELOP  
WITH THE STRONG NW FLOW CAA AND FALLING TEMPS BEHIND THE ARCTIC  
COLD FRONT.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 1216 PM EST THU FEB 11 2016  
 
NOT MUCH HAS CHANGED IN THE LAST 24 HOURS. THE DOWNWARD TREND  
CONTINUES AT MAPLE RAPIDS...WHICH HAS ALLOWED US TO DROP THE  
ADVISORY AT THAT LOCATION.  
 
THIS MORNINGS OBSERVATIONS ON THE GRAND RIVER AT ROBINSON TWP SHOW  
SMALL...THIN PIECES OF ICE FLOWING IN THE RIVER. A FEW RIVER  
GAUGES THROUGHOUT SOUTHWEST LOWER MICHIGAN ARE BEGINNING TO SHOW  
SIGNS OF BEING AFFECTED BY ICE. AT THIS POINT IT IS NOT AN ISSUE.  
HOWEVER...TEMPERATURES WILL ONLY CONTINUE TO GET COLDER THROUGH  
THE WEEKEND. THIS WILL SUPPORT ADDITIONAL ICE FORMATION THROUGH AT  
LEAST SUNDAY MORNING WITH OVERNIGHT TEMPERATURES IN THE SINGLE  
DIGITS. SOMETHING TO CONSIDER IS THAT WE ARE LATE IN THE WINTER  
SEASON AND WATER TEMPERATURES ARE LOW ENOUGH THAT ICE DEVELOPMENT  
COULD OCCUR FAIRLY QUICKLY WITH LONG PERIODS OF SUB-FREEZING AIR.  
 
OVERALL PRECIPITATION AMOUNTS ARE STILL LOW THROUGH THE NEXT 7  
DAYS. ASIDE FROM ANY LOCAL HEAVY LAKE EFFECT SNOWFALL THAT  
OCCURS...OVERALL AMOUNTS WILL BE FAIRLY LIGHT. EVEN THIS WILL NOT  
BE REALIZED UNTIL MELTING TAKES PLACE. THE MAIN CONCERN WILL BE  
RIVER FLUCTUATION DUE TO ICE IN THE EVENT THAT THICK ICE DEVELOPS.  
 

 
   
GRR WATCHES/WARNINGS/ADVISORIES
 
 
MI...WINTER STORM WARNING FROM 7 AM FRIDAY TO 4 PM EST SATURDAY FOR  
MIZ064-071.  
 
WINTER WEATHER ADVISORY FROM 7 AM TO 7 PM EST FRIDAY FOR MIZ044-  
057-065.  
 
WINTER WEATHER ADVISORY FROM 7 AM FRIDAY TO 4 PM EST SATURDAY  
FOR MIZ037-038-043-050-056-072.  
 
LM...GALE WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY MORNING FOR  
LMZ844>849.  
 
HEAVY FREEZING SPRAY WARNING FROM 7 PM FRIDAY TO 7 AM EST  
SATURDAY FOR LMZ844>849.  
 
SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR LMZ844>849.  
 

 
 

 
 
UPDATE...04  
SYNOPSIS...WDM  
SHORT TERM...WDM  
LONG TERM...LAURENS  
AVIATION...EBW  
HYDROLOGY...JAM  
MARINE...LAURENS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MI Page
The Nexlab IN Page Main Text Page