Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 140820
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
420 AM EDT MON APR 14 2014

.UPDATE...
ISSUED AT 945 PM EDT SUN APR 13 2014

LATEST WV IMAGERY SHOWS IMPRESSIVE COMMA CLD OVER THE NCENTRAL CONUS
ASSOCIATED WITH SHRTWV NEAR OMAHA MOVING SLOWLY NEWD. OTHER SHRTWVS
DIGGING SEWD OVER SCENTRAL CANADA AND INTO THE WRN PLAINS ARE ACTING
TO DEEPEN THE UPR TROF IN THE CENTRAL CONUS. RA SHIELD WITHIN AREA
OF DEEP MSTR SHOWN ON THE 00Z GRB RAOB AND IN ADVANCE OF ASSSOCIATED
SFC LO MOVING INTO NW IL IS MOVING INTO THE SCENTRAL COUNTIES THIS
EVNG. MUCH COLDER AIR IS POISED JUST TO THE NW OF UPR MI. THE
AIRMASS IN MN IS ALSO RATHER DRY IN THE LLVLS.

ALTHOUGH THE PCPN ASSOCIATED WITH THIS DISTURBANCE AND UNDER DEEP
LYR QVECTOR CNVGC/UPR DVGC IN RIGHT ENTRANCE OF UPR JET STREAK IN
ONTARIO WL BEGIN AS RA...SHORT TERM MODELS SHOW WBZ HGTS FALLING
STEADILY NW-SE WITH VIGOROUS DYNAMIC COOLING AND ARRIVAL OF NEAR SFC
DRIER AIR THAT HAS ALREADY MOVED INTO THE WRN CWA. SO EXPECT THE RA
TO CHG TO SN NW-SE AND BY THE EARLY MRNG HRS ON MON OVER THE SE CWA
AS SFC LO IS FCST TO SHIFT INTO NRN LWR MI. MANY OF THE HIER RES
MODELS SHOW STORM TOTAL QPF OF 0.50 TO 0.75 INCH OVER THE E HALF OF
THE CWA IN A 6-9 HR PERIOD...CONSISTENT WITH H7 SPECIFIC HUMIDITY
FCST AS HI AS 4 G/KG OVER THE SE CWA. OTHER DYNAMIC FORCING WL
INCLUDE BAND OF H7 FGEN FCST OVER THE CENTRAL CWA TO THE NW OF H7 LO
TRACK OVER NW LK MI PARALLEL TO SW H5 FLOW. THESE FEATURES INDICATE
DEFORMATION ZN WL IMPACT MUCH OF THE SE HALF OF THE CWA. MODELS ALSO
SHOW H925 N WINDS INCRSG UP TO 35-40 KTS LATE TNGT/MON MRNG...AND
THIS UPSLOPE FLOW WL ENHANCE SN TOTALS INTO MARQUETTE COUNTY...WHICH
WL NOT BE POSITIONED AS FVRBLY RELATIVE TO THE DYNAMIC SUPPORT.
OPTED TO ISSUE ADVY FOR THE CWA TO THE SE OF A LINE FM THE HURON
MNTS TO IRON COUNTY FOR SN...WHICH WL END IN THE 12Z-18Z MON TIME
FRAME AS THE SFC LO/DYNAMIC SUPPORT SHIFT TO THE E. THE STRONG N
WINDS WL ALSO CAUSE BLSN...MAINLY NEAR LK SUP INTO MON MRNG BEFORE
THE WINDS GRDLY DIMINISH.
&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 343 PM EDT SUN APR 13 2014

UPPER AIR PATTERN CONSISTS OF A SHORTWAVE OVER LAKE HURON...ANOTHER
OVER CENTRAL KANSAS WHICH IS GETTING EJECTED OUT OF A TROUGH IN THE
NORTHERN ROCKIES. THE TROUGH MOVES INTO THE NORTHERN PLAINS TONIGHT
AND INTO THE UPPER MISSISSIPPI RIVER VALLEY ON MONDAY. NAM BRINGS IN
SOME 850-500 MB Q-VECTOR CONVERGENCE AND DEEPER MOISTURE INTO THE
CWA TONIGHT. BEST MOISTURE APPEARS TO STAY TO THE SOUTH AND EAST OF
THE CWA AND WILL HAVE THE HIGHEST POPS ACROSS THE EAST HALF OF THE
CWA. GFS AND ECMWF SHOW 850-500 MB Q-VECTOR CONVERGENCE MOVING
ACROSS THE AREA AS WELL TONIGHT AND MONDAY.

LATEST MODEL RUNS HAVE BROUGHT THE PCPN A BIT FURTHER WEST AGAIN
WITH THE ECMWF A BIT FURTHER WEST AS WELL. BECAUSE OF THIS...QPF AND
SNOW AMOUNTS WERE BUMPED UP SLIGHTLY OVER THE EASTERN CWA. LOOKS
LIKE THIS EVENT COULD SEE 2 TO 6 INCHES OF SNOW OVER THE EASTERN CWA
AND ISSUED A SNOW ADVISORY FOR ALGER...LUCE AND NORTHERN SCHOOLCRAFT
COUNTIES. STILL LOOKS LIKE THE EVENT WILL START OUT AS RAIN OVER THE
EASTERN CWA BEFORE THE PCPN SWITCHES OVER TO SNOW. USED WET BULB
ZERO HEIGHTS FOR THE WEATHER POTENTIAL GRIDS. WILL HAVE HIGHEST POPS
OVER THE EASTERN AND SOUTHERN CWA AND LOWEST POPS IN THE FAR WEST
AND NORTH. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST AND STORM WILL PULL OUT MONDAY AFTERNOON.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 417 AM EDT MON APR 14 2014

LONGWAVE TROUGH AXIS ACROSS THE GREAT LAKES ON TUESDAY. QUITE CHILLY
WITHIN THE TROUGH WITH H85 TEMPS DOWN TO -20C OVER LK SUPERIOR.
SHORTWAVE DROPPING SE IN THE MEAN TROUGH INCREASES DEPTH OF QUALITY
OF MOISTURE AND ALSO STEEPENS H9-H7 LAPSE RATES ON TUESDAY. LAKE
EFFECT FLURRIES MAY TRANSITION TO DIURNALLY DRIVEN SNOW SHOWERS WITH
COVERAGE EXTENDING INLAND TOWARD WI BORDER AND LK MICHIGAN SHORE.
POPS LOW CHANCE AT BEST THOUGH. TEMPS WILL BE VERY COOL FOR THIS
TIME OF YEAR WITH READINGS IN THE LOW-MID 20S NORTH AND AROUND 30
IN THE SOUTHERN CWA. NORMAL HIGHS ARE INTO THE LOWER 50S OVER THE
SOUTH. WAVE MOVES EAST ON TUESDAY EVENING WHICH SHOULD ALLOW SKIES
TO TEMPORARILY CLEAR OUT AHEAD OF NEXT SYSTEM THAT BEGINS TO IMPACT
FAR WEST CWA WITH LGT SNOW LATE TUESDAY NIGHT. MIN TEMPS MAY DIP
INTO SINGLE DIGITS FOR MANY AREAS BEFORE THICKER CLOUDS MOVE BACK
IN LATER DURING THE NIGHT.

WHAT TO DO WITH SYSTEM FOR WEDNESDAY WILL BECOME LARGER FOCUS ONCE
WE GET PAST SYSTEM BRINGING SNOW TO MUCH OF UPR MICHIGAN TODAY. WILL
TWO CAMPS STILL PRESENT IN THE MODELS. NAM/GFS BRING SHORTWAVE AND SFC
LOW PRESSURE AND INVERTED TROUGH ACROSS UPPER MISSISSIPPI RIVER
VALLEY QUICKER...AND HAVE MORE QPF. BOTH CAMPS OF MODELS GENERATE QPF
INTO WESTERN CWA BY 12Z WEDNESDAY...SUPPORTED BY LARGER SCALE
DIFFLUENCE ALOFT BTWN JETS EMERGING FM THE PLAINS AND CROSSING LK
SUPERIOR REGION. ECMWF AND GEM-NH AND UKMET ARE SLOWER AND NOT AS
HEAVY WITH QPF OVER UPR MICHIGAN...KEEPING FOCUS FOR HEAVIER PRECIP
OVER CNTRL MN INTO WCNTRL WI ALONG TRACK OF SFC LOW PRESSURE WAVE
THROUGH MUCH OF WEDNESDAY BEFORE LIFTING IT ACROSS MAINLY WESTERN
HALF OF UPR MICHIGAN LATER WEDNESDAY INTO WEDNESDAY NIGHT. DESPITE
MODEL DIFFERENCES...ENOUGH EVIDENCE TO PUSH POPS TO LIKELY WEDNESDAY
AND WEDNESDAY NIGHT. ALSO THERE IS DECENT AGREEMENT THAT WESTERN AND
PROBABLY CENTRAL CWA WILL SEE MODERATE SNOW AMOUNTS FROM THIS
SYSTEM...WITH BULK OF SNOW FALLING WEDNESDAY AFTN THROUGH EARLY
THURSDAY MORNING. MIXING RATIOS 2.5-3G/KG WOULD SUPPORT MODERATE SNOW
AMOUNTS OF 3 TO 6 INCHES OVER 12 HOUR PERIOD. MODELS SHOWING AREA OF
MID-LEVEL FGEN...FAIRLY STRONG CONSIDERING HOW FAR OUT WE ARE
STILL...THAT COULD RESULT IN BANDS OF HEAVIER SNOW OVER LIKELY THE
WEST CWA. HPC HEAVY SNOW GRAPHICS SHOW MUCH OF FAVORED AREA WITH
MODERATE PROBABILITY OF SEEING 4 INCHES OF SNOW WITH LOW PROBABILITY
OF SEEING 8 INCHES. BASED ON 1000-850MB AND 850-700MB THICKNESSES AND
H85 TEMPS...SNOW WILL MIX WITH AND COULD CHANGE TO RAIN LATER
WEDNESDAY NIGHT OVER SCNTRL AND EAST CWA. RAIN/SNOW MIX CONTINUES
INTO THURSDAY FOR THOSE AREAS WHILE WIDESPREAD SNOW DIMINISHES
ELSEWHERE. NO WATCH ATTM...AS IT WOULD BE LATER 5TH PERIOD AND STILL
NEED TO GET THROUGH THIS ONGOING SNOW SYSTEM TO AVOID ANY CONFUSION.
WILL CONTINUE TO MENTION IN EHWO/HWOMQT.

LATER THURSDAY AND ON INTO NEXT WEEKEND THE FORECAST IS AT BEST
MUDDLED...WHICH LEADS TO LOWER THAN AVERAGE CONFIDENCE FOR SURE. GFS
MORE OR LESS IS FAIRLY CONSISTENT IN SHOWING SHORTWAVE IN SOUTHERN
STREAM LIFTING ACROSS UPPER GREAT LAKES WHILE PHASING WITH NORTHERN
BRANCH SHORTWAVE TROUGH. RESULT IS WRAPPED UP SFC LOW WITH
WIDESPREAD RAIN AND SNOW OVER UPR MICHIGAN. GEM-NH SUPPORTS IDEA
SOMEWHAT THOUGH IT IS SLOWER AND NOT AS STRONG. ECMWF WAS TRENDING
NORTH AND WEST WITH THAT SYSTEM...BUT WITH LATEST RUN NOW HAS WENT
BACK TO THE SOUTHEAST...KEEPING MUCH OF UPR MICHIGAN DRY ON FRIDAY.
ECMWF IS NOT PHASING THE SOUTHERN WAVE NEAR AS MUCH AS GFS ATTEMPTS
TO SHOW. CONSENSUS POPS...CAPPED AT LOW CHANCE...WILL BE UTILIZED
FOR NOW. WHATEVER LOW PRESSURE SYSTEM WOULD BE EXITING TO START THE
WEEKEND...WITH HIGH PRESSURE AND DRIER WEATHER FOR THE REST OF THE
WEEKEND AS SHOWN BY GFS. NOT SO INDICATES THE ECMWF...WITH A QUICK
PUSH OF NEXT SHORTWAVE ENERGY AND SFC TROUGH/RAIN SHOWERS FOR
SUNDAY. LATEST RUN BACKED OFF SOME...BUT JUST SHOWS THE HIGH
VARIABILITY THAT CURRENTLY EXISTS FOR THAT FORECAST TIME FRAME. ONE
PRETTY SURE THING IS IT LOOKS LIKE WARMING TREND /TEMPS TRYING TO
RETURN TOWARD AVERAGE/ DEVELOPS NEXT WEEKEND AFTER WHAT APPEARS TO
BE A CHILLY MID APRIL WEEK.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 138 AM EDT MON APR 14 2014

SAW...A LO PRES MOVING FM IOWA THRU NRN LWR MI MON MRNG WL BRING A
PERIOD OF SN TO SAW EARLY THIS MRNG. WITH AN INCRSG N UPSLOPE WIND
THAT WL GUST AS HI AS 30 KTS AND CONTRIBUTE TO SOME BLSN AS WELL...
EXPECT CONDITIONS TO DETERIORATE TO IFR/LIFR FOR AT LEAST SEVERAL
HRS THRU 12Z. THE ARRIVAL OF DRIER AIR...DAYTIME HEATING AND SLOWLY
WEAKENING PRES GRADIENT/WINDS WL BRING MVFR CONDITIONS AFT SUNRISE
ON MON.

IWD/CMX...SN ASSOCIATED WITH THE LO PRES MOVING THRU THE LKS LATE
TNGT WL MISS THESE LOCATIONS TO THE E. BUT WITH A FVRBL...INCRSG
UPSLOPE N WIND AT IWD...MVFR CIGS SHOULD PREDOMINATE AT THAT
LOCATION. BEST CHC FOR SOME IMPROVEMENT TO VFR AT IWD WL BE MON
AFTN...WHEN DAYTIME HEATING MIGHT LIFT THE CLD BASE INTO THE VFR
RANGE. SINCE THIS N WIND IS NOT AS FVRBL FOR CMX AND THE INCOMING
LLVL AIRMASS IS ON THE DRY SIDE...THIS SITE WL EXPERIENCE PERIODS OF
VFR CIGS.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 AM EDT MON APR 14 2014

NORTH GALES 35-40 KNOTS FOR TODAY...MAINLY EAST HALF...AS LOW
PRESSURE SYSTEM TRACKS ACROSS LOWER MICHIGAN THIS MORNING AND
EVENTUALLY ACROSS QUEBEC BY THIS EVENING. WINDS QUICKLY DIMINISH
BY THIS EVENING AND SHOULD REMAIN BLO 20 KTS OVER MOST OF THE LAKE
THROUGH TUESDAY. LOW PRESSURE SYSTEM LIFTING ACROSS UPPER GREAT
LAKES LATER ON WEDNESDAY WILL RESULT IN EAST TO NORTHEAST WINDS UP
TO 25 KTS OVER MAINLY WESTERN LAKE INTO THURSDAY. WINDS DIMINISH TO
LESS THAN 20 KTS REST OF THE FORECAST PERIOD.
&&

.HYDROLOGY...
ISSUED AT 417 AM EDT MON APR 14 2014

REPORTS OF ICE JAMS IN DELTA COUNTY SUNDAY ON ESCANABA RIVER AND
ASSOCIATED TRIBUTARIES. HYDROLOGIC STATEMENT WAS ISSUED SUNDAY
EVENING AND THIS IS VALID THROUGH THIS EVENING. PRECIPITATION OCCURS
MAINLY IN THE FORM OF SNOW TODAY. OPPORTUNITIES FOR WIDESPREAD
PRECIPITATION ALSO IN THE FORECAST FOR WEDNESDAY THROUGH THURSDAY...
AND POSSIBLY FRIDAY. FEASIBLE THAT TOTAL PRECIPITATION FOR THIS WEEK
MAY EXCEED AN INCH IN SOME AREAS OF UPPER MICHIGAN. THIS PRECIP
ADDED TO EXISTING SNOWPACK WITH WATER EQUIVALENT OF 4-9 INCHES
OVER MAINLY WESTERN UPPER MICHIGAN WILL RESULT IN ANOTHER PERIOD
OF SNOWMELT AND RUNOFF ONCE WARMER TEMPERATURES MOVE BACK INTO THE
REGION BY NEXT WEEKEND.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER WEATHER ADVISORY UNTIL 7 AM CDT THIS MORNING FOR MIZ010-
     011.

  WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR MIZ006-
     007-013-014-085.

  WINTER WEATHER ADVISORY UNTIL 11 AM EDT /10 AM CDT/ THIS MORNING
     FOR MIZ005-012.

LAKE SUPERIOR...
  GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ249>251-266-
     267.

  GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ244-245-264-
     265.

LAKE MICHIGAN...
NONE.
&&

$$

UPDATE...KC
SHORT TERM...07
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
HYDROLOGY...JLA





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