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237
FXUS63 KMQT 291743
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
143 PM EDT FRI AUG 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EDT FRI AUG 29 2014

AN UPPER TROUGH OVER THE CENTRAL UNITED STATES WILL BE THE MAIN
CONTROLLING FACTOR TO THE WEATHER OVER THE NEXT COUPLE OF DAYS.
WATER VAPOR IMAGERY IS SHOWING ABUNDANT MOISTURE STREAMING
NORTHEAST OVER THE REGION BUT A BULK OF THE SHORTWAVE ENERGY IS
STILL HANGING BACK CLOSER TO THE UPPER TROUGH AXIS STRETCHING
NORTH/SOUTH FROM SOUTH DAKOTA TO NORTHERN TEXAS. THE FIRST WAVE OF
PRECIPITATION ASSOCIATED WITH THIS UPPER TROUGH IS SLIDING
NORTHEAST INTO THE REGION EARLY THIS MORNING. INITIAL PRECIPITATION
HAS BEEN STRUGGLING TO MAKE A DENT IN THE EXISTING DRY AIR SEEN
BETWEEN 800-550MB ON THE 00Z KGRB SOUNDING BUT IT IS GETTING INTO
NORTHEAST WISCONSIN AND SOUTH CENTRAL UPPER MICHIGAN. THIS
PRECIPITATION IS FORCED BY ISENTROPIC ASCENT ON 300-320K
SURFACES AND THE INITIAL WAVE WILL SLIDE NORTHEAST ACROSS THE
SOUTHEAST HALF OF UPPER MICHIGAN THIS MORNING. WITH THE ISENTROPIC
ASCENT STRETCHING TO THE WEST ACROSS NORTHERN WISCONSIN...COULD SEE
SHOWERS DEVELOPING THERE EARLY THIS MORNING...BUT THINK THE
PRECIPITATION CHANCES FOR THE WESTERN U.P. WILL BE TIED TO THE AREA
OF CONVECTION/SHOWERS IN SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND
SOUTHWEST WISCONSIN. THESE SHOWERS HAVE BEEN MAKING A SLOW PUSH TO
THE NORTHEAST AND WOULD LIKELY PUSH NORTH ACROSS THE AREA LATE THIS
MORNING AND EARLY THIS AFTERNOON. BEHIND THESE TWO WAVES...THINK
THERE WILL A LULL IN THE PRECIP AS THE BEST LARGE SCALE FORCING IS
OFF TO THE WEST AND CLOSER TO THE UPPER TROUGH AXIS THAT WILL MOVE
INTO THE AREA TONIGHT. WITH NO SIGNIFICANT MID LEVEL THERMAL
ADVECTION BEHIND THE INITIAL WAVE THIS AFTERNOON...WONDERING IF
PORTIONS OF CENTRAL/EASTERN UPPER MICHIGAN WILL STAY DRY.

FARTHER TO THE WEST THIS AFTERNOON...A THE SURFACE-925MB TROUGH OR
WARM FRONT WILL SETUP OVER WESTERN LAKE SUPERIOR AND PORTIONS OF
WESTERN UPPER MICHIGAN. THIS LOW LEVEL FORCING WITH PLENTY OF
MOISTURE SHOULD BE ENOUGH TO KICK OFF SOME SHOWERS LATER THIS
AFTERNOON AND INTO THE EVENING HOURS. THIS AREA WILL CONTINUE TO BE
THE FOCUS INTO TONIGHT AS THE UPPER LEVEL TROUGH AND SURFACE LOW
(CURRENTLY WEST OF SIOUX FALLS) MOVE CLOSER TO THE AREA. THIS WILL
BRING BETTER DEEP FORCING AND MID LEVEL FGEN FROM WEST TO EAST
THROUGH THE NIGHT. THUS...WILL RAMP POPS UP TO DEFINITE VALUES OVER
THE WESTERN THIRD OF THE U.P. DURING THE EVENING AND SLOWLY SHIFT
THEM EAST WITH THE SURFACE/UPPER TROUGH.

AS FOR RAIN AMOUNTS...HAVE TRENDED THEM BACK FOR THE MORNING HOURS
TODAY (ESPECIALLY WEST) BASED OFF THE LATEST RADAR AND HIGH
RESOLUTION MODEL TRENDS. BEST OPPORTUNITY FOR MODERATE TO HEAVY
RAIN WILL COME TONIGHT OVER THE WESTERN HALF OF UPPER MICHIGAN
WHERE THE BEST FORCING IS LOCATED ALONG THE SURFACE TROUGH AND
EXTRA CONVERGENCE FROM THE SECONDARY TROUGH (CURRENTLY IN SOUTHERN
MANITOBA AND NORTH DAKOTA) THAT MERGES WITH THE EXISTING TROUGH.
THE HEAVY RAIN POTENTIAL IS ALSO AIDED BY PWAT VALUES ARE AROUND
1.5-1.75 INCHES OVER THE WEST (175 PERCENT OF NORMAL)...WARM CLOUD
LAYER OVER 11KFT...AND GENERALLY SLOW STORM MOTION VALUES. GOING
FORECAST HAS AROUND 0.75-1.00 INCH FOR MUCH OF WESTERN UPPER
MICHIGAN (MATCHING 03Z SREF 30 PERCENT PROBS OF 1IN/12HRS) AND THAT
COULD BE HIGHER WHERE ANY THUNDERSTORMS OCCUR. WILL CONTINUE THE
IDEA OF THE PREVIOUS SHIFT OF THUNDER STAYING SOUTH OF THE AREA FOR
THE FIRST PART OF THE MORNING...THEN STARTED TO NOSE SLIGHT CHANCES
IN THROUGH THE REST OF THE DAY BEHIND THE 925-850MB WARM FRONT.
TONIGHT...WILL TRANSITION TO CHANCE THUNDER ACROSS THE AREA DUE TO
THE BETTER FORCING AND MUCAPE VALUES BETWEEN 300-800 J/KG.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 439 AM EDT FRI AUG 29 2014

A RATHER UNSETTLED LABOR DAY WEEKEND LOOKS TO BE IN STORE FOR UPPER
MICHIGAN...ALTHOUGH SUNDAY LOOKS LIKE IT WILL REMAIN DRY. THE SHORT
WAVE TROUGH MOVING THROUGH THE WESTERLY FLOW ALOFT WILL PASS ACROSS
UPPER MICHIGAN ON SATURDAY. RAIN/RAIN SHOWERS WILL LIKELY BE ONGOING
ACROSS MUCH OF THE FORECAST AREA SATURDAY MORNING WITH DEEP MOISTURE
OVER THE REGION AND MODERATE MID LEVEL Q-VECTOR CONVERGENCE UNDER
THE RIGHT ENTRANCE REGION OF THE UPPER JET. BEST RAIN WILL LIKELY BE
ACROSS THE CENTRAL AND EAST THROUGH EARLY AFTERNOON WHERE THE
DEFORMATION AXIS WILL BE LOCATED. WITH PRECIPITABLE WATER VALUES
STILL AROUND 175 PERCENT OF NORMAL SATURDAY...THERE IS STILL AN
OPPORTUNITY FOR MODERATE RAINFALL ESPECIALLY WITH THE WARM CLOUD
DEPTH STILL AROUND 11 KFT. ONLY NEGATIVE TO HEAVY RAINFALL WOULD BE
THE LACK OF SIGNIFICANT INSTABILITY WHICH WOULD KEEP DEEPER
CONVECTION FROM BEING A CONCERN. AS SUCH...WILL RAISE POPS TO
CATEGORICAL ACROSS THE ENTIRE FORECAST AREA ON SATURDAY...WITH
DIMINISHING POPS DURING THE AFTERNOON.

WITH CONTINUED TROUGHINESS ACROSS THE EAST IN THE EVENING...WILL
HOLD ONTO CHANCE POPS UNTIL THE TROUGH AXIS PASSES EAST. MAIN
CONCERN SATURDAY NIGHT WILL BE THE FOG DEVELOPMENT. WITH THE
WIDESPREAD RAINFALL ON SATURDAY COMBINED WITH WEAK HIGH PRESSURE
BUILDING ACROSS THE UPPER GREAT LAKES...IT WOULD SEEM LIKE A
FAVORABLE ENVIRONMENT FOR DENSE FOG DEVELOPMENT SAT NIGHT INTO
SUNDAY MORNING. OTHERWISE...SUNDAY SHOULD BE A FAIRLY QUIET DAY WITH
WEAK HEIGHT RISES ACROSS THE AREA AHEAD OF THE DEEPER TROUGH OVER
THE PLAINS. THIS SHOULD ALLOW TEMPS TO RISE TO CLOSE TO NORMAL AS
MOST OF THE LOWER CLOUD SHOULD HAVE DISSIPATED IN THE MORNING HOURS.

THE PLAINS UPPER TROUGH MOVES EASTWARD SUNDAY NIGHT INTO MONDAY.
MODELS ARE IN QUITE GOOD AGREEMENT IN SHOWING THE TROUGH AND
ASSOCIATED COLD FRONT TO PASS THROUGH THE AREA MONDAY MORNING. THE
MORNING TIMING SHOULD PRECLUDE ANY SIGNIFICANT CHANCE FOR SEVERE
WEATHER DESPITE THE STRONG WIND FIELDS AND 50 KT LLJ. AT LEAST RIGHT
NOW...IF THERE WERE TO BE ANY SEVERE WEATHER WITH THIS SYSTEM ACROSS
UPPER MICHIGAN...IT WOULD OCCUR IN THE LATE MORNING INTO THE
AFTERNOON ACROSS THE CENTRAL AND THE EASTERN U.P. RIGHT ALONG THE
FRONT AND WHEN THE LEFT EXIT REGION OF THE JET IS OVERHEAD. WILL
MAINTAIN LIKELY POPS STARTING ACROSS THE WEST SUN NIGHT AND THEN
ACROSS THE ENTIRE FORECAST AREA ON MONDAY.

FOR THE REMAINDER OF THE EXTENDED...ZONAL FLOW DEVELOPS ACROSS THE
NORTHERN TIER AS A BROAD RIDGE EXTENDS ACROSS THE SOUTH. THE WEATHER
WILL STAY GENERALLY QUIET AND SEASONABLE TUE AND WED WITH WEAK SFC
HIGH PRES IN CONTROL. BETTER CHANCES FOR SHOWERS AND STORMS BY
THURSDAY WITH A FRONTAL BOUNDARY MOVING INTO THE AREA IN W-NW FLOW.
AT THIS TIME...IT LOOKS LIKE THU COULD END UP BEING FAIRLY WARM
AHEAD OF THIS FRONT IF THE ECMWF VERIFIES. BEYOND THURSDAY...IT
LOOKS LIKE ANOTHER COOL DOWN FOR NEXT WEEKEND WITH CANADIAN HIGH
PRESSURE JUST TO OUR NORTH.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 140 PM EDT FRI AUG 29 2014

PERIOD OF SHOWERS AND LOW CIGS EXPECTED TO CONTINUE THROUGH THE
FORECAST PERIOD AT ALL SITES.

AT IWD...NO OBSERVATIONS IN OVER 48 HOURS HAVE MADE TAF PREPARATION
VERY DIFFICULT...BUT DO EXPECT POOR CONDITIONS TO PERSIST.

AT CMX...THINK THAT THE SITE WILL SEE RAIN MORE OFTEN THAN NOT...BUT
SOME DRY PERIODS WILL OCCUR WITH HIGHER CIGS AT THE TIME. THE TIMING
OF BETTER CONDITIONS IS DIFFICULT IF NOT IMPOSSIBLE TO PREDICT GIVEN
THE NATURE OF THE PRECIPITATION. THUNDER CHANCES SHOULD STAY SE OF
THE TAF SITE. CONDITIONS WILL IMPROVE ON SATURDAY...BUT IT SHOULD BE
AROUND OR AFTER THE END OF THE TAF PERIOD.

AT SAW...EXPECT SOME IMPROVEMENT THIS AFTERNOON/EVENING AS LOW LEVEL
MIXING INCREASES. CIGS SHOULD THEN GO BACK DOWN LATE THIS EVENING
THROUGH SATURDAY MORNING AS GREATER LOW LEVEL MOISTURE RETURNS.
THERE WILL BE DRY PERIODS WITH HIGHER CIGS...BUT TIMING THOSE OUT IS
DIFFICULT AT BEST. THUNDERSTORMS ARE POSSIBLE THIS EVENING DEPENDING
ON THE AMOUNT OF CLEARING AND INSTABILITY THAT CAN FORM.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 501 AM EDT FRI AUG 29 2014

HIGH PRESSURE CONTINUES TO SHIFT AWAY FROM THE UPPER GREAT LAKES
REGION THIS MORNING AND INTO THE NEW ENGLAND STATES TODAY. AS THIS
OCCURS...SOUTHEASTERLY FLOW WILL BE IN THE 15-20KT RANGE. THAT
SOUTHEASTERLY FLOW WILL CONTINUE OVER THE EASTERN HALF OF THE LAKE
TONIGHT...WHILE THE WESTERN HALF DIMINISHES BELOW 10KTS AS A
SURFACE TROUGH MOVES OVER THAT AREA. THIS TROUGH WILL PUSH
SOUTHEAST ACROSS THE REST OF THE LAKE BY SATURDAY AFTERNOON AND
SWITCHING WINDS TO THE NORTHWEST 10-20KTS. AFTER LIGHT WINDS
SATURDAY NIGHT...SOUTHEASTERLY WINDS WILL INCREASE ON SUNDAY AHEAD
OF THE NEXT TROUGH THAT WILL MOVE ACROSS LAKE SUPERIOR ON MONDAY.
WINDS UP TO 25KTS ARE POSSIBLE AHEAD OF THIS TROUGH SUNDAY NIGHT
INTO MONDAY.

FINALLY...AREAS OF FOG WILL DEVELOP OVER PORTIONS OF LAKE SUPERIOR
THIS AFTERNOON AND CONTINUE INTO SUNDAY MORNING. SOME LOCATIONS
COULD EXPERIENCE DENSE FOG...ESPECIALLY OVER NORTHEAST LAKE
SUPERIOR.
&&

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

$$

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







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