Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 291842
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
242 PM EDT WED JUL 29 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EDT WED JUL 29 2015

FAIRLY IMPRESSIVE SURFACE AND UPPER LOW FOR LATE JULY IS LOCATED
JUST TO THE SOUTH OF LAKE WINNIPEG EARLY THIS MORNING...AND IT IS
KEEPING MUCH OF ITS ENERGY NEAR THE LOW IN MANITOBA. THIS HAS LED TO
A FAIRLY UNEVENTFUL PASSAGE OF THE COLD FRONT DUE TO THE LACK OF ANY
UPPER LEVEL SUPPORT/SHORTWAVES MOVING THROUGH THE AREA AND THE MID-
LEVEL DRY AIR AND CAPPING SEEN ON RAP ANALYSIS SOUNDINGS. THERE WAS
A THUNDERSTORM THAT MOVED NORTHEAST OUT OF NORTHWEST WISCONSIN
EARLIER IN THE NIGHT BUT DISSIPATED OVER WESTERN LAKE SUPERIOR. HAVE
SEEN SOME LIGHT SHOWER DEVELOPMENT OVER THE WESTERN U.P. OVER THE
LAST 1-2HRS AND THEY ARE MOVING NORTHEAST WHILE THE FRONT SHIFTS
THEM TO THE EAST. THERE HASN/T BEEN ANY LIGHTNING NOTED WITH THEM
THUS FAR...LARGELY DUE TO THEM STRUGGLING TO GET ABOVE THE FREEZING
LEVEL (HAVE PEAKED AROUND 15KFT). STILL THINK SOME THUNDER IS
POSSIBLE AS THEY ALIGN WITH A THIN AREA OF 500 J/KG OF MUCAPE AHEAD
OF THE FRONT AS SEEN ON THE SPC MESOSCALE ANALYSIS PAGE. THE COLD
FRONT WILL CONTINUE TO THE EAST THIS MORNING AND EXIT THE AREA BY
NOON. WILL CONTINUE TO SHOW SLIGHT CHANCE POPS RIGHT ALONG THE FRONT
AS IT MOVES EAST THIS MORNING...BUT DON/T EXPECT ANYTHING MORE THAN
AN ISOLATED SHOWER/THUNDERSTORM. HAVE SEEN A FAIRLY SIGNIFICANT DROP
IN DEWPOINTS BEHIND THE FRONT...AS KIWD WENT FROM A 72 DEGREE
DEWPOINT AT 535Z AND QUICKLY DROPPED TO 64 AT 615Z AND IS NOW AT 57
AT 735Z.

BEHIND THE FRONT...THE DRY SLOT SEEN ON WATER VAPOR IMAGERY WILL
MOVE THROUGH THE AREA AND LEAD TO AN AREA OF MOSTLY SUNNY START TO
THE DAY OVER THE WEST. DO EXPECT THE AREA OF CLOUDS IN NORTHEAST ND
AND NORTHWEST MN TO MOVE EAST INTO THE WESTERN CWA THIS AFTERNOON
AND BE AIDED BY DIURNAL HEATING TO PRODUCE DIURNAL CU ON THE LEADING
EDGE AND AHEAD OF THE CLOUDS INTO THE CENTRAL U.P. OVER THE
EAST...AFTER A CLOUDY START TO THE DAY...EXPECT A PERIOD OF MOSTLY
SUNNY SKIES AND THEN SOME DIURNAL CU IN AFTERNOON AND LINGERING INTO
THE EVENING. HIGHS TODAY WILL BE IN THE UPPER 70S OVER THE WEST AND
THE LOW-MID 80S OVER THE CENTRAL AND EAST.

THE MAIN HAZARD BEHIND THE FRONT WILL BE THE GUSTY WEST-SOUTHWEST
WINDS. THESE WINDS WILL BE AIDED BY THE TIGHT PRESSURE GRADIENT OVER
THE NORTHWEST HALF OF THE CWA AND LARGELY OVER NORTHWESTERN LAKE
SUPERIOR. HAVE ALREADY SEEN GUSTS TO 20-25KTS IMMEDIATELY BEHIND THE
FRONT EARLIER IN THE NIGHT AND CLOSER TO THE LOW WINDS HAVE BEEN
GUSTING TO 30-35KTS IN NORTHWEST MINNESOTA. THE AMPLE SUNSHINE THIS
MORNING WILL HELP TO MIX INTO THE 25-40KT WINDS AROUND 925MB TO THE
SURFACE...WITH THE STRONGEST WINDS OVER THE KEWEENAW PENINSULA. IN
THAT AREA...WOULD EXPECT GUSTS TO AROUND 35KTS BY MID AFTERNOON AND
THERE COULD BE A BRIEF PERIOD OF GUSTS TO 40KTS BY EARLY EVENING.
DON/T THINK THERE WILL BE A LONG ENOUGH PERIOD FOR A WIND ADVISORY
FOR THE KEWEENAW PENINSULA (NEED 39KTS)...SO WILL ISSUE AN SPS FOR
KEWEENAW AND NORTHERN HOUGHTON COUNTIES TO HIGHLIGHT THE WINDY
CONDITIONS FOR TODAY. THE REST OF THE U.P. WILL SEE WIND GUSTS OF 20-
30KTS...HIGHEST OVER THE WEST.

WITH THE MUCH DRIER AIR MOVING INTO THE AREA...THINK DEWPOINTS WILL
MIX OUT INTO THE UPPER 40S TO AROUND 50 OVER THE WEST/CENTRAL TODAY.
WHILE TEMPERATURES WILL BE COOLER THAN YESTERDAY...RH VALUES WILL
STILL FALL INTO THE 30S. THAT WILL LEAD TO AN ELEVATED RISK OF
WILDFIRES ACROSS MUCH OF THE U.P. TODAY. SINCE THE RH VALUES WILL BE
ABOVE RED FLAG CRITERIA...THIS SITUATION WOULD FALL UNDER AN RFD
PRODUCT DUE TO THE FREQUENT GUSTS OVER 25 MPH. SINCE COORDINATION
NEEDS TO BE DONE WITH FIRE WX USERS BEFORE ISSUANCE...WILL PASS
ALONG TO DAY SHIFT TO COORDINATE POTENTIAL ISSUANCE.

A SECONDARY TROUGH MOVES EAST ACROSS THE AREA TONIGHT. SOME CLOUDS
ASSOCIATED WITH IT...LARGELY OVER LAKE SUPERIOR...BUT NOT EXPECTING
ANY RAIN. THERE WILL STILL BE STRONG WINDS JUST ABOVE THE SURFACE
AGAIN TONIGHT...WHICH WILL HELP TO KEEP THE WINDS FROM DECOUPLING.
HAVE KEPT UP GUSTS OVER THE KEWEENAW PENINSULA (TO 20-30KTS)
...ESPECIALLY FOR THE EXPOSED LOCATIONS. OTHERWISE...THE REST OF THE
AREA WILL SEE WINDS TURNING WESTERLY WITH GUSTS TO 10-20KTS (HIGHEST
NORTH).

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 239 PM EDT WED JUL 29 2015

IMPACTS...WITH LIMITED CHANCES FOR PRECIP...WILL HAVE TO KEEP
WATCHING FIRE WEATHER.

A LOW PRESSURE SYSTEM WILL HANG OUT OVER HUDSON BAY FROM THU NIGHT
THROUGH AT LEAST THE WEEKEND...SENDING SEVERAL WAVES ACROSS THE AREA
THROUGH DURING TIME. PREDICTABILITY OF THE WAVES IS POOR AS MODELS
STRUGGLE TO CONSISTENTLY RESOLVE THE FEATURES. AVAILABLE MOISTURE IS
ALSO ON THE LOW SIDE...LIMITING PRECIP COVERAGE AND AMOUNTS. WILL
KEEP SLIGHT CHANCE POPS OVER AT LEAST PORTIONS OF THE AREA EACH
PERIOD. TEMPERATURES LOOK TO BE NEAR NORMAL.

FRI LOOKS PRETTY DRY WHEN LOOKING AT THE SFC RH DROPPING INTO THE MID
TO UPPER 30 PERCENT RANGE. WINDS WILL GUSTS TO 20-25MPH...MAKING FOR
SOMEWHAT ELEVATED FIRE WEATHER CONCERNS.

MODELS SHOW THE LOW SHIFTING TO THE SE IN THE EARLY TO MIDDLE PART
OF NEXT WEEK...BUT HOW MUCH AND HOW FAST IS UNCERTAIN. IT DOES LOOK
LIKE BETTER PRECIP CHANCES WILL RESULT FROM THE SHIFT AND SUBSEQUENT
COLD FRONTAL PASSAGE...TIMING OF THAT IS ALSO UNCERTAIN...BUT SUN
NIGHT INTO MON LOOKS LIKE BEST BET FOR NOW. WIDESPREAD PRECIP STILL
MAY NOT OCCUR ALONG THE STRONGER WAVE AND COLD FRONTAL PASSAGE.
TEMPS LOOK TO DROP TO BELOW NORMAL VALUES MON THROUGH WED.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 144 PM EDT WED JUL 29 2015

GUSTY WEST-SOUTHWEST WINDS ARE EXPECTED AT ALL THREE SITES
THIS AFTEROON...WITH THE HIGHEST GUSTS (TO AROUND 35KTS) EXPECTED AT
KCMX. THE WINDS WILL DIMINISH SOME AT ALL THREE SITES TONIGHT...BUT
STILL EXPECT GUSTS TO 25KTS AT KCMX. VFR CU/SC CIG IS EXPECTED
THROUGH THIS AFTERNOON AT IWD/CMX WITH FEW-SCATTERED VFR CLOUDS WITH
LINGERING INTO TONIGHT. OTHERWISE...EXPECT MAINLY JUST SCT CU AT
SAW.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 AM EDT WED JUL 29 2015

A STRONG LOW PRESSURE SYSTEM FOR LATE JULY IS LOCATED NEAR LAKE
WINNIPEG EARLY THIS MORNING AND IT WILL LIFT NORTHEAST INTO FAR
NORTHERN ONTARIO TODAY. MEANWHILE...IT WILL SWEEP A COLD FRONT
CURRENTLY OVER CENTRAL LAKE SUPERIOR EAST ACROSS THE REST OF THE
LAKE THIS MORNING. BEHIND THE FRONT...SOUTHWEST WINDS WILL
INCREASE THROUGH THE MORNING OVER THE WESTERN HALF OF THE LAKE AND
PRODUCE GALES TO 35-40KTS. THERE COULD BE A FEW GUSTS IN THE 40-45KT
RANGE TOWARDS ISLE ROYALE THIS AFTERNOON. THESE WINDS WILL DECREASE
AND SHIFT TO THE WEST THIS EVENING AS THE FIRST IN A SERIES OF
TROUGHS MOVE ACROSS LAKE SUPERIOR THROUGH SUNDAY MORNING (ASSOCIATED
WITH THE SURFACE LOW SLOWLY DRIFTING OVER HUDSON BAY). THERE IS THE
POTENTIAL FOR GALES OUT OF THE WEST-NORTHWEST TONIGHT BEHIND THE
SECONDARY TROUGH AS THE PRESSURE GRADIENT REMAINS TIGHT OVER
NORTHERN LAKE SUPERIOR. BUT EXPECT THE MARINE LAYER TO BE THE
STRONGEST IN THAT AREA WITH THE WATER TEMPERATURES STILL IN THE
UPPER 30S AND LOWER 40S. WILL ADD A MENTION OF GALE FORCE GUSTS FOR
NOW. THE PRESSURE GRADIENT WILL GRADUALLY DECREASE THROUGH THE REST
OF THE WEAK AS ADDITIONAL WEAK SURFACE TROUGHS MOVE SOUTHEAST ACROSS
THE LAKE. EXPECT WINDS TO STAY BELOW 25KTS AFTER THURSDAY AND
THROUGH THE WEEKEND.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
     240>242-245>247-263.

  GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ264.

  GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LSZ243-244.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...TITUS
AVIATION...JLB
MARINE...SRF



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