Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 291751
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
151 PM EDT TUE JUL 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM EDT TUE JUL 29 2014

UPPER TROUGH CENTERED NEAR JAMES BAY SLOWLY DRIFTS WESTWARD THROUGH
TONIGHT. WEAK SFC TROUGH IS CURRENTLY CROSSING NORTHERN UPR MICHIGAN
WHILE ANOTHER FRONT...PRETTY WEAK AS WELL...IS STILL TO NORTH OF LK
SUPERIOR. PASSAGE OF THE SECOND FRONT TONIGHT SHOULD ALLOW FOR MORE
RIDGING AT THE SFC TO DEVELOP BY LATE TONIGHT. HARD TO TIME SHORTWAVES
ALONG WITH POCKETS OF DEEPER MOISTURE AND INCREASED INSTABILITY WILL
DRIVE THE SHOWER/THUNDER CHANCES OVER UPR MICHIGAN INTO TONIGHT.
FOLLOWING PERSISTENCE AND TRENDS FROM LAST COUPLE DAYS...EXPECT
MAXIMUM OF COVERAGE TO SHRA AND TSRA TO OCCUR WHERE THESE FEATURES
SYNC UP WITH PEAK HEATING OF THE DAY. NWS RADAR LOOP FM THE UPPER
GREAT LAKES REGION...THANKFULLY INCLUDING MQT RADAR AGAIN...ALONG
WITH RADAR IMAGERY FROM ENVIRONMENT CANADA INDICATES RELATIVE MINIMUM
IN SHRA/TSRA ATTM OVER UPR MICHIGAN. AREA OF ENHANCED SHOWERS WITHIN
RIBBON OF HIGHER H7-H5 RH AND ELEVATED MUCAPE UP TO 300 J/KG IS
DROPPING SOUTHWARD ACROSS PORTIONS OF NORTHWEST ONTARIO AND THE
MINNESOTA ARROWHEAD.

MAJORITY OF SHORT TERM MODELS IN GOOD AGREEMENT THAT THE AREA OF
DEEPER MOISTURE AND SHORTWAVE/ASSOCIATED H7-H5 Q-VECTOR CONVERGENCE
TO NORTHWEST OF LK SUPERIOR THIS MORNING CROSSES THE AREA LATER THIS
MORNING INTO MID AFTN. BY LATE AFTN...AXIS OF HIGHER RH AND MLCAPE
UP TO 500J/KG WILL BE MORE ORIENTED FM WESTERN UPR MICHIGAN TO
SCNTRL UPR MICHIGAN. MEANWHILE...EXPECT A MINIMUM IN FORCING AND
MOISTURE AND MLCAPES FM ISLE ROYALE TO EASTERN UPR MICHIGAN. SHOWED
HIGHEST POPS OVER THE INTERIOR WEST AND CENTRAL LATE MORNING INTO
MID AFTN. AFTER THE ISOLD SHRA AROUND THROUGH DAYBREAK DEPART OVER
THE EAST CWA...LIMITED DEEPER MOISTURE AND DIRECT IMPACT FM THE
INCOMING SHORTWAVE RESULTS IN LITTLE IF ANY ADDITIONAL CHANCES OF
RAIN TODAY. SIMILAR HIGH TEMPS TO YDY...WITH 60S NEAR LK SUPERIOR
AND INTO THE LWR 70S OVER THE SCNTRL.

CAPE DURING PEAK HEATING OF THE DAY CONTINUES TO APPEAR MORE SKINNY
WITH NORMALIZED CAPE VALUES LESS THAN 0.1. EFFECTIVE SHEAR MAY TRY
TO REACH 30-35 KTS THIS AFTN...BUT OVERALL SETUP OF MORE CLOUDS AND
LESS REALIZED INSTABILITY SUPPORTS STRONGER STORMS STAYING FARTHER
SOUTH AND WEST OF CWA WHERE MLCAPES ARE MORE TOWARD 1000J/KG THIS
AFTN. EVEN SO...CANNOT COUNT OUT AN ISOLD STRONG STORM OVER THE WEST
HALF OF THE CWA EARLY TO MID AFTN...ESPECIALLY AWAY FM THE KEWEENAW.
MEAN STORM MOTION/H7 WINDS ARE ORIENTED NW TO SE BUT MORE ORGANIZED
OR STRONGER STORMS WOULD MOVE MORE NORTH TO SOUTH...SIMILAR TO ISOLD
STORM THAT OCCURRED EARLIER TONIGHT OVER NORTHWEST WI JUST TO WEST
OF KIWD.

MODELS AGREE THAT RIBBON OF DEEPER MOISTURE DROPS SOUTH OF THE AREA
TONIGHT WHILE GENERALLY THERE IS SUBSIDENCE/Q-VECTOR DIVERGENCE OVER
UPR MICHIGAN. SHOWERS AND THUNDERSTORMS FM LATE THIS AFTN SHOULD FADE
AWAY QUICKLY THIS EVENING NEAR WI BORDER WITH NEGATIVE DYNAMICS AND
LOSS OF DAYTIME HEATING. ANOTHER BATCH OF MID-LEVEL MOISTURE AND
UVM CURRENTLY JUST TO WEST OF JAMES BAY IS FORECAST TO STAY MAINLY
TO THE EAST OF LK SUPERIOR...SO OTHER THAN INCREASING MID CLOUDS
LATER TONIGHT AS THIS DROPS SOUTH...DID NOT CARRY ANY ADDITIONAL
CHANCES OF SHRA/TSRA. COULD SEE FOG OVERNIGHT AS RIDGING AND LIGHT
WINDS TAKE HOLD...ESPECIALLY OVER THE WEST HALF WHERE RAIN IS MORE
LIKELY TODAY.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 334 AM EDT TUE JUL 29 2014

THE UPPER LEVEL LOW CENTERED NEAR JAMES BAY WILL PERSIST THROUGH
THE REST OF THE WORK WEEK...BEFORE GRADUALLY WEAKENING AND LIFTING
NORTHEAST THIS WEEKEND AND INTO EARLY NEXT WEEK. WITH A RIDGE OVER
THE WESTERN CONUS/CANADA...EXPECT THE FLOW ALOFT TO BE OUT OF THE
NORTHWESTERLY DIRECTION THROUGH THE LONG TERM PERIOD AND LEAD TO
TEMPERATURES BEING A LITTLE BELOW NORMAL. 850MB TEMPS WILL BE THE
COOLEST ON WEDNESDAY...AROUND 8C...BEFORE RISING TO AROUND 12C ON
THURSDAY AND REMAINING INTO THE WEEKEND. THUS...EXPECT WEDNESDAY TO
HAVE THE COOLEST HIGHS OF THE WORK WEEK (IN THE UPPER 60S AND LOWER
70S). WHILE HIGHS WILL BE A FEW DEGREES BELOW NORMAL ON WEDNESDAY
EXPECT A GRADUAL TREND TO NEAR NORMAL TEMPERATURES BY FRIDAY AND
CONTINUE INTO THE WEEKEND.

AS FOR PRECIPITATION...EXPECT GENERALLY DIURNAL SHOWERS OVER
INTERIOR LOCATIONS FOR WEDNESDAY THROUGH FRIDAY...ALTHOUGH THE
SEVERAL SHORTWAVES ROTATING AROUND THE UPPER LOW COULD LEAD TO A
COUPLE PERIODS OF SHOWERS DURING THE OVERNIGHT HOURS. ON
WEDNESDAY...THINK COVERAGE WILL BE FAIRLY LIMITED (AND OVER THE
SOUTH CENTRAL OR MAYBE EAST) AS THE MAIN SHORTWAVE ENERGY BRUSHES
THE NORTHEAST HALF OF THE CWA. DEEP MOISTURE APPEARS TO BE THE
MAIN LIMITING FACTOR BUT THERE IS A POCKET OF MOISTURE THAT
ROTATES THROUGH DURING THE DAY BETWEEN 800-700MB. THUS...WILL KEEP
POPS IN THE SLIGHT OR LOW CHANCE CATEGORY FOR MAINLY THE CENTRAL
AND EAST AWAY FROM THE STABILITY OF LAKE SUPERIOR. THERE ARE HINTS
OF A WEAK SHORTWAVE PRODUCING A FEW SHOWERS ON WEDNESDAY
NIGHT...BUT CONFIDENCE IS TOO LOW IN INCLUDE ANYTHING MORE THAN
SLIGHT CHANCE OF SHOWERS. THURSDAY SHOULD BE SIMILAR TO
WEDNESDAY...BUT WITH A LITTLE BETTER FOCUS OVER THE SOUTH CENTRAL
DUE TO THE POTENTIAL OF A STRONGER LAKE BREEZE OFF LAKE MICHIGAN.
WILL HAVE THE HIGHEST POPS ON FRIDAY (HIGH END CHANCES)...AS MODELS
CONTINUE TO INDICATE A STRONGER UPPER TROUGH ROTATING THROUGH DURING
THE DAY. IT APPEARS SUBSIDENCE BEHIND FRIDAY/S TROUGH SHOULD LEAD TO
A DRY SATURDAY. THUS...HAVE CONTINUE THE DOWNWARD TREND IN POPS.
PRECIP CHANCES WILL INCREASE ON SUNDAY AFTERNOON/NIGHT AS ANOTHER
SHORTWAVE DROPS SOUTHEAST ACROSS THE AREA. THIS WAVE MAY PROVIDE
SOME REAMPLIFICATION OF THE UPPER TROUGH AND CONTINUE PRECIPITATION
CHANCES INTO MONDAY.

FINALLY...FOR THUNDER POTENTIAL...MLCAPE VALUES ARE BELOW 500 J/KG
ON WEDNESDAY AFTERNOON AND WILL CAP AT SLIGHT CHANCES.
THURSDAY/FRIDAY HAVE MLCAPE VALUES A TOUCH HIGHER OVER THE SOUTH
CENTRAL...SO WILL HAVE CHANCES THERE AND SLIGHT ELSEWHERE WHERE
THERE ARE POPS IN THE AFTERNOON. FRIDAY WILL ALSO BE HELPED BY THE
SHORTWAVE...BUT WITH 0-6KM SHEAR VALUES STILL WEAK (15-20KTS) NOT
EXPECTING ANYTHING MORE THAN BRIEF HEAVY RAIN AND SOME SMALL HAIL IN
ANY OF THE STRONGER STORMS.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 150 PM EDT TUE JUL 29 2014

SHOWERS AND ISOLATED THUNDERSTORMS ARE MOVING ACROSS PARTS OF THE
AREA AND ARE EXPECTED TO INCREASE IN COVERAGE THROUGH THE AFTERNOON.
WENT WITH VCSH AT CMX AND SAW BECAUSE BEST COVERAGE IS EXPECTED TO
BE S OF THOSE AIRPORTS. AT IWD...WENT WITH VCSH BECAUSE COVERAGE OF
SHOWERS IS UNCERTAIN SINCE THEY HAVE NOT DEVELOPED YET...BUT BETTER
COVERAGE IS QUITE POSSIBLE THERE.

EXPECT FOG DEVELOPMENT AT ALL SITES TONIGHT...BUT AM UNCERTAIN ON
THE EXTENT OF THE DEVELOPMENT.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 AM EDT TUE JUL 29 2014

WITH A WEAK PRESSURE GRADIENT TYPICAL OF SUMMER DOMINATING THIS
FORECAST PERIOD...EXPECT WINDS UNDER 20 KTS THRU THE WEEK.
&&

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

$$

SHORT TERM...JLA
LONG TERM...SRF
AVIATION...TITUS
MARINE...KC






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