Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 281918
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
318 PM EDT SUN JUN 28 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 315 PM EDT SUN JUN 28 2015

NW FLOW ALOFT COMBINED WITH DAYTIME HEATING/INSTABILITY AND RESIDUAL
LOW-LEVEL BOUNDARIES AND EVER PRESENT LAKE BREEZE BOUNDARIES KICKED
OFF CLUSTERS OF SHRA/TSRA THIS AFTN. THUS FAR...MAIN AREA OF TSRA
HAVE OCCURRED WHERE BOUNDARY WAS SEEN THIS MORNING OUT OF LINGERING
CLOUD/ACCAS FIELD LEFTOVER FM THE SCT SHRA/TSRA THAT OCCURRED LAST
EVENING OVER WESTERN UPR MICHIGAN. WEAK SHEAR LESS THAN 20 KTS HAS
KEPT STRENGTH OF STORMS IN CHECK. A COUPLE OF THE STORMS SO FAR HAVE
BEEN DECENT LIGHTNING PRODUCERS WITH ONE REPORT OF SMALL HAIL WITH
THE STORM NEAR MUNISING. STRONGEST STORMS WERE WHERE THE MORNING
BOUNDARY INTERSECTED LAKE SUPERIOR BREEZE EARLY THIS AFTN. ANOTHER
CLUSTER OF SHRA/TSRA WERE OVER ALGER AND SCHOOLCRAFT COUNTIES ALONG
THE LAKE SUPERIOR LAKE BREEZE AND WHERE MLCAPES WERE TOWARD
1000J/KG. EXPECT THESE CLUSTERS OF SHRA/TSRA TO GRADUALLY FADE AWAY
WITH LOSS OF DAYTIME HEATING. CANNOT DROP POPS COMPLETELY THOUGH AS
MOST OF CWA WILL BE WITHIN H85-H7 TROUGH AXIS AND ENHANCED MOISTURE
ALONG THAT AXIS. MAY BE SIMILAR TO WHAT OCCCURRED LAST NIGHT WITH
SMALLER FEATURES DRIVING ISOLD SHRA/TSRA. ADDED FOG LATE TONIGHT FOR
AREAS THAT HAVE SEEN MORE PERSISTENT RAIN THIS AFTN. LOWS IN THE 50S
FOR MAJORITY OF CWA.

COLD FRONT CURRENTLY OVER NORTHERN ONTARIO AND CNTRL MANITOBA SWINGS
SOUTH TOWARD UPPER GREAT LAKES MONDAY AFTN. SEEMS THAT MAIN
SHORTWAVE TRACKS MORE OVER FAR WESTERN UPR MICHIGAN AND INTO WI/MN.
TROUGH IS PRESENT AT H85-H7 AND THIS ALONG WITH DAYTIME HEATING AND
INSTABILITY SHOULD SUPPORT ANOTHER ROUND OF SHRA/TSRA AS CONVECTIVE
TEMPS IN THE MID 70S ARE REACHED BY EARLY AFTN. NAM/GFS SEEM TOO
HIGH WITH DWPNTS INTO THE MID 60S AND THUS HAVE MLCAPES NEARING
2000J/KG. BASED ON UPSTREAM OBS AND LIMITED CHANGE IN AIRMASS WITH
MINIMAL ADVECTION...EXPECT DWPNTS TO BE MORE AROUND 60F ON MONDAY
AFTN AS TEMPS PUSH INTO THE UPR 70S. PREFER THE GEM-REGIONAL AND
SREF SHOWING MLCAPES OF AT LEAST 500 J/KG BUT NOT TOO MUCH ABOVE
1000 J/KG. WINDS ALOFT REMAIN LIGHT SO DEEP LAYER SHEAR IS LESS THAN
20 KTS. ON ITS OWN...THAT WOULD SUGGEST NO SEVERE STORMS. SUPPOSE IF
NAM/GFS ARE CORRECT WITH THEIR 2000+ J/KG OF SFC BASED CAPE AND 1500+
OF MLCAPE...THEN PULSE TYPE SEVERE STORMS ARE POSSIBLE. SIMILAR TO
TODAY...COULD ALSO SEE STORMS BECOME STRONGER VCNTY OF LAKE BREEZES.
OVERALL THINK THERE IS ONLY A LIMITED RISK OF SEVERE STORMS FOR
MONDAY AFTN. WOULD SAY IT WILL BE A SIMILAR SETUP TO WHAT IS
OCCURRING TODAY...BUT YOU JUST NEVER KNOW WITH SUMMERTIME SHRA/TSRA.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 401 AM EDT SUN JUN 28 2015

MAIN CONCERNS THROUGH THE EXTENDED ARE THE STRENGTH OF THE STORMS
MONDAY AFTERNOON AND THE OVERALL COVERAGE OF STORMS LATER IN THE
WEEK AND FOR THE FOURTH. BROAD TROUGHING WILL BE IN PLACE OVER MUCH
OF THE EASTERN CONUS WITH A STRONG RIDGE OVER THE WEST.

MONDAY THROUGH TUESDAY...A SURFACE RIDGE WILL CONTINUE TO SLIDE TO
THE EAST OF THE AREA THROUGH THE DAY MONDAY. AS THIS HAPPENS...A
COLD FRONT AND COLLOCATED UPPER LEVEL SHORTWAVE WILL SLIDE INTO THE
WESTERN U.P. THE BIG QUESTION IS THE AMOUNT OF INSTABILITY THAT WILL
BE AROUND TO ALLOW SOME OF THESE STORMS TO BECOME SEVERE. TIMING OF
THE FRONT WOULD BE FAVORABLE FOR MAXIMUM INSTABILITY AS MANY OF THE
MODELS PLACE THE FRONT OVER THE WEST TO CENTRAL U.P. DURING PEAK
HEATING MONDAY AFTERNOON. THE 00Z/28 GFS IS STILL THE MOST
AGGRESSIVE WITH MUCAPE VALUES IN THE 2000-3000 J/KG RANGE WHILE THE
GENERAL CONSENSUS OF THE REMAINING MODELS WOULD KEEP IT AT A BIT
MORE MODEST AT 1000 TO 1500 J/KG...GENERALLY CONFINED TO THE
INTERIOR WEST AND ALONG THE WI BORDER. SHEAR VALUES ARE FAIRLY WEAK
FOR ANY WIDESPREAD ORGANIZED SEVERE WEATHER...WITH DEEP LAYER SHEAR
VALUES GENERALLY ON THE ORDER OF 15 TO 20 KTS. THE MOST LIKELY MODE
INITIALLY WOULD BE PULSE THUNDERSTORMS WITH A FEW ISOLATED SEVERE
STORMS IN THE NORTHWEST FLOW. THE MAIN THREATS WOULD LIKELY BE
MARGINALLY SEVERE HAIL AND STRONG WIND GUSTS WITH A BIT DRIER AIR
BELOW 800MB. THE COLD FRONT AND SHORTWAVE WILL CONTINUE ACROSS THE
U.P. THROUGH MONDAY NIGHT...REACHING THE EASTERN U.P. BY 06Z
TUESDAY. THIS WILL KEEP CONTINUED CHANCE OF SHOWERS AND
THUNDERSTORMS ACROSS THE AREA THROUGH THIS TIME
PERIOD...HOWEVER...ANY SEVERE POTENTIAL WILL LIKELY DIMINISH WITH
LOSS OF DAYTIME HEATING. AS THE FRONT SHIFTS EAST TUESDAY...THE EAST
HALF OF THE U.P. WILL CONTINUE TO BE UNDER THE TROUGH AXIS KEEPING
SLIGHT CHANCES OF RAIN SHOWERS IN THE FORECAST IN THE MORNING.
TUESDAY AFTERNOON...THIS WAVE WILL SLIDE EASTWARD AND A SURFACE
RIDGE WILL SLIDE INTO THE WEST HALF OF THE U.P. EFFECTIVELY SHIFTING
MOST OF THE PRECIPITATION OUT OF THE AREA. CLOUD COVER WILL LIKELY
LINGER EVEN AFTER THE RAIN DIMINISHES WITH MOISTURE LINGERING BEHIND
THE SYSTEM.

TUESDAY NIGHT THROUGH THURSDAY...THE AFOREMENTIONED DRY HIGH
PRESSURE SYSTEM WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES
THROUGH THIS TIME PERIOD. THIS WILL KEEP MAINLY LIGHT WINDS AND
MOSTLY CLEAR SKIES IN THE FORECAST. THE LIGHT WINDS...CLEAR SKIES
AND GENERAL TROUGHING OVER THE AREA WILL ALLOW TEMPERATURES TO FALL
BELOW NORMAL TUESDAY NIGHT AND WEDNESDAY NIGHT. OVERNIGHT LOWS WILL
LIKELY FALL INTO MID 40S FOR THE INLAND LOCATION WITH A FEW OF THE
COLDER SPOTS POSSIBLY SEEING UPPER 30S. TO PUT IT IN
PERSPECTIVE...NORMAL LOWS THIS TIME OF YEAR ARE IN THE LOW 50S.

THURSDAY NIGHT THROUGH THE EXTENDED...MODELS HAVE THE NEXT LOW
PRESSURE SYSTEM AND UPPER LEVEL WAVE SLIDING ACROSS CENTRAL CANADA
THURSDAY NIGHT...REACHING HUDSON BAY AROUND 12Z FRIDAY. A COLD FRONT
EXTENDING SOUTH FROM THE LOW WILL PUSH CLOSER TO THE WESTERN U.P.
FRIDAY MORNING AND INTO THE EASTERN U.P. BY SATURDAY MORNING. ALONG
AND AHEAD OF THE FRONT...SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE...ESPECIALLY DURING THE DAY FRIDAY. MODELS ARE GENERALLY
PUSHING THE COLD FRONT EAST OF THE AREA BY THE FOURTH OF JULY
ALLOWING FOR DRIER CONDITIONS AND COOLER AIR. WILL HAVE TO SEE IF
THE WAVE SLIDES FAR ENOUGH EAST TO KEEP SHOWERS FROM LINGERING
DURING THE DAY SATURDAY. AT THIS POINT WILL STICK WITH A CONSENSUS
OF THE MODELS.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 146 PM EDT SUN JUN 28 2015

DAYTIME HEATING HAS LED TO ISOLD SHRA/TSRA POPPING UP MAINLY OVER
WESTERN AND CENTRAL UPR MICHIGAN. COULD SEE TERMINALS AFFECTED WITH
THIS ACTIVITY THIS AFTN...THOUGH THERE IS NOT ENOUGH CERTAINTY TO GO
WITH ANYTHING MORE THAN VCSH. CONDITIONS WILL REMAIN VFR. MID CLOUDS
WITH ISOLD SHRA POSSIBLE TONIGHT...THEN ANOTHER CHANCE OF SHRA AND
TSRA LATE MONDAY MORNING INTO MONDAY AFTN AS COLD FRONT DROPS TOWARD
UPR MICHIGAN FM NORTHERN MINNESOTA AND ONTARIO. ATTM APPEARS GREATEST
CHANCE OF TSRA ON MONDAY AFTN WOULD BE AT KIWD AND KSAW FARTHER AHEAD
OF THE COLD FRONT AND WHERE MORE INSTABILITY WILL RESIDE.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 315 PM EDT SUN JUN 28 2015

LIGHT WINDS BELOW 20 KNOTS ARE EXPECTED THROUGH THE ENTIRE FORECAST
PERIOD. PATCHY FOG WILL PERSIST ACROSS THE LAKE THROUGH TUE MORNING
AS A RELATIVELY MOIST AIRMASS REMAINS OVER THE REGION.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLA
LONG TERM...KEC
AVIATION...JLA
MARINE...07


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