Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 280816
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
416 AM EDT MON JUL 28 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM EDT MON JUL 28 2014

UPPER TROUGH AND COOLER WEATHER PATTERN HAS BECOME ESTABLISHED AND
PERSISTS THROUGH THE WEEK. FOR TODAY...PRIMARY SFC LOW PRESSURE
SYSTEM THAT BROUGHT THE SHOWERS AND THUNDERSTORMS TO THE AREA ON
SUNDAY IS TRACKING ACROSS UPSTATE NEW YORK AND NORTHWEST PENNSYLVANIA
EARLY THIS MORNING WHILE HIGH PRESSURE OVER THE CANADIAN PRAIRIES
EXPANDS SOUTH ACROSS THE CENTRAL PLAINS. SCT-BKN MID CLOUDS ARE
QUICKLY FILLING IN FM MINNESOTA ACROSS WESTERN AND NORTH CENTRAL LK
SUPERIOR AND OVER ONTARIO. AT FIRST GLANCE...SETUP INTO TONIGHT
APPEARS TO SUPPORT MAINLY DRY WEATHER. HOWEVER...NEED TO CONSIDER
SHORTWAVE/ENHANCED CLOUD CURRENTLY DROPPING SOUTH ACROSS NORTHEAST
MANITOBA AND FAR NORTHWEST ONTARIO. 00Z RAOB FROM CYYQ IN NORTHERN
MANITOBA INDICATED ONLY NARROW MOIST LAYER AROUND H6 WITH THIS
WAVE...WITH VERY DRY AIR BLO H6. YET UPSTREAM ATTM...NIGHTTIME
SATELLITE FOG PRODUCT DOES SHOW EXPANDING SHROUD OF CLOUD WITH OBS OF
BKN070 AND SCT140. SEEMS THAT AS SHORTWAVE DROPS SOUTH TODAY...BKN
MID CLOUDS WILL SPREAD OVER MUCH OF UPR MICHIGAN. FORECAST SOUNDINGS
INDICATE NAM IS MOST BULLISH ON DEPTH OF MOISTURE /HIGHER RH FM H85
THROUGH H6/ COMPARED TO GFS AND RUC13 /NARROWER AREA OF HIGHER RH
CENTERED ON H7/. A SUBTLE DIFFERENCE FOR SURE...BUT THIS WILL IMPACT
SHOWER POTENTIAL FOR LATER TODAY.

FORCING WITH THE SHORTWAVE DOES NOT APPEAR TO BE THAT STRONG OR
WIDESPREAD AS PVA AND H85-H5 Q-VECTOR CONVERGENCE IS QUITE WEAK WITH
THE WAVE. SEEMS THAT THE H8-H7 LIFT/UVM PRESENT IS MOSTLY DUE TO THE
COLD TEMPS ALOFT ALONG TRACK OF SHORTWAVE. THIS RESULTS IN SOME
MARGINALLY STEEP MID-LEVEL LAPSE RATES AND POCKET OF 50+ TOTAL
TOTALS.

TRENDED TOWARD MORE CLOUDS TODAY WITH THE INCOMING SHORTWAVE. THIS
ADJUSTMENT RESULTED IN A LOWERING OF MAX TEMPS. BASED ON MIXING TO
H9 WITH ONSHORE NORTHWEST FLOW NEAR LK SUPERIOR AND CLOUDS...WENT MID
60S NEAR LK SUPERIOR AND BASED ON MIXING TO H85 HAVE AROUND 70
INLAND. NOW ONTO THE THOSE SHOWER CHANCES. NAM/NCEP WRF-ARW/WRF-NMM
AND LOCAL WRF RUNS INDICATE SCATTERED QPF MAXIMIZING IN THE AFTN
DURING PEAK HEATING. DPROG/DT OF NAM AND GFS INDICATE GOOD RUN TO RUN
CONSISTENCY IN THE LAST FEW MODEL RUNS. SIGNALS MIXED THOUGH AS GEM-
REGIONAL WHICH ONCE SHOWED DECENT QPF HAS BACKED OFF AND THE ECMWF
SHOWS LITTLE QPF. RUC13...WHICH SHOWS A LOT OF MID CLOUDS... LOOKS
SIMILAR TO GEM-REGIONAL WITH LITTLE QPF OVER LAND AREAS OF UPR
MICHIGAN. LOCAL WRF POINTS TO ISOLD SHRA OVER FAR SCNTRL...WHICH DOES
MAKE SENSE AS IT IS FURTHER AWAY FM MODIFICATION/STABILIZATION OFF LK
SUPERIOR. THINKING THE NAM IDEA IS OVERDONE DUE TO HOW IT IS HANDLING
THE DEPTH OF THE MOISTURE AND SINCE IT ALSO HAS TEMPS INTO THE MID
70S WITH DWPNTS IN THE MID 50S RESULTING IN TOO MUCH SFC BASED
INSTABILITY. EVEN SO...A ROUGE SHOWER IS NOT OUT OF THE QUESTION WITH
THE MOISTURE ADVECTION AND SOME HEATING. BY FAR THE BETTER SHOT AT
SHOWERS SHOULD BE LATE THIS AFTN INTO THE EVENING OVER WESTERN LK
SUPERIOR AND WESTERN UPR MICHIGAN DUE TO UVM FM SHORTWAVE/COLD POOL.
SMALL CHANCE OF SHOWERS...QUITE ISOLD IN COVERAGE...SHOULD SLIDE
ACROSS REST OF CWA THROUGH THE NIGHT AS THE SHORTWAVE CROSSES THE
AREA WHILE SHEARING OUT. ANOTHER SHORTWAVE WILL BE MOVING TOWARD
NORTH CENTRAL LK SUPERIOR LATE TONIGHT...BUT THIS WILL MAINLY AFFECT
THE FORECAST INTO TUESDAY.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 336 AM EDT MON JUL 28 2014

OVERALL...LIMITED CHANGES TO THE GOING FORECAST AS MODELS REMAIN
CONSISTENT IN THE HIGHLY AMPLIFIED (FOR LATE JULY) FLOW PATTERN
REMAINS OVER THE THE AREA THROUGH THE UPCOMING WORK WEEK. THIS
WILL PLACE THE UPPER GREAT LAKES REGION UNDER NORTH TO NORTHWEST
FLOW ALOFT AS THE AREA IS BETWEEN THE UPPER RIDGE OVER THE ROCKIES
AND THE UPPER LOW ROTATING NEAR JAMES BAY. DISTURBANCES ROTATING
AROUND THE UPPER LOW WILL PERIODICALLY DROP THROUGH THE
REGION...WHICH COMBINED WITH DIURNAL HEATING LEAD TO A LARGELY
AFTERNOON/EVENING SHOWER AND OCCASIONAL THUNDERSTORM POTENTIAL. THE
BEST OPPORTUNITY FOR PRECIPITATION REMAINS ON TUESDAY...AS THE
STRONGEST DISTURBANCE AND WEAK SURFACE TROUGH DROP SOUTHEAST THROUGH
THE AREA. WILL CONTINUE TO SHOW RISING POPS THROUGH THE MORNING AND
PEAKING IN THE MID-LATE AFTERNOON HOURS BEFORE DIMINISHING THROUGH
THE EVENING. 0-6KM SHEAR STILL LOOKS UNIDIRECTIONAL AND AROUND
20-25KTS AND WITH MLCAPE VALUES GENERALLY 200-700 J/KG (AND SKINNY
WITH NCAPE VALUES BELOW 0.08) DON/T EXPECT ANY SEVERE THREAT AT
THIS POINT. WOULDN/T BE SURPRISED TO SEE SOME LOCATIONS ALONG THE
WISCONSIN BORDER OR SOUTH CENTRAL THAT SEE BETWEEN 0.25-0.50IN OF
RAIN...ALTHOUGH THE EXACT LOCATION WILL DEPEND ON WHERE THE
HEAVIEST SHOWERS TRACK.

THE REST OF THE WEEK WILL BE DEPENDENT ON THE TIMING OF THE
SHORTWAVES. ONLY HAVE SLIGHT CHANCES OF DIURNALLY DRIVEN SHOWERS
(MAINLY INTERIOR TOWARDS WISCONSIN BORDER) ON WEDNESDAY DUE TO THE
AREA BEING BETWEEN WAVES AND AS A RESULT A LITTLE DRIER MID LEVEL
AIR IN THE AREA. THERE ARE INDICATIONS THAT A STRONGER WAVE WILL
ROTATE AROUND THE UPPER LOW SOMEWHERE BETWEEN WEDNESDAY AFTERNOON
AND THURSDAY MORNING...WHICH WOULD LIKELY LEAD TO SOME SHOWERS
DEPENDING ON WHEN IT MOVES THROUGH AND HAVE SLIGHT CHANCES FOR
WEDNESDAY NIGHT TO ACCOUNT FOR THAT. AFTER THAT POINT WAVES BECOME
SUBTLE THROUGH THURSDAY NIGHT AND A SURFACE RIDGE TRIES TO NOSE BACK
EAST INTO THE AREA FROM THE DAKOTAS. THUS...WILL CONTINUE DIURNAL
SLIGHT CHANCES TOWARDS THE WISCONSIN BORDER DURING THAT PERIOD. WILL
SHOW BETTER CHANCES ON FRIDAY AFTERNOON WITH HELP FROM LAKE BREEZES
OVER THE CENTRAL/EAST. AS FOR TEMPERATURES DURING THIS WORK
WEEK...THE BELOW NORMAL 850MB TEMPS AND COOLER FLOW OFF LAKE
SUPERIOR WILL LEAD TO HIGH TEMPERATURES A LITTLE BELOW NORMAL.

FOR THE WEEKEND...THE UPPER LOW NEAR JAMES BAY WILL BROADEN AND
LIFT TO THE NORTHEAST WHILE THE RIDGE OVER THE WEST REMAINS IN
PLACE. MEANWHILE...MODELS ARE INDICATING WEAK TROUGHING TO REMAIN
OVER THE EASTERN CONUS AND WILL CONTINUE THE NORTHWEST FLOW ALOFT
OVER THE CWA. THUS...EXPECT THE TEMPERATURES TO REMAIN SLIGHTLY
BELOW NORMAL. IN ADDITION...EVEN THOUGH A WEAK HIGH PRESSURE RIDGE
WILL BE OVER THE AREA...THERE WILL BE THE POTENTIAL FOR DIURNALLY
DRIVEN ISOLATED TO SCATTERED SHOWERS AROUND LAKE BREEZES ON
SATURDAY AS THE UPPER TROUGH AXIS SLIDES THROUGH. THERE IS THE
POTENTIAL SUNDAY WILL END UP DRY...BUT WITH THE PATTERN WE ARE
IN HAVE LEFT SLIGHT CHANCE POPS IN FOR NOW.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 127 AM EDT MON JUL 28 2014

EXPECT VFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD AS DRIER
AIRMASS SHOWN ON THE 00Z INL AND YPL RAOBS SLIDES TO THE S. THERE
MAY BE SOME SHALLOW GROUND FOG WITH OCNL LOWER VSBYS THRU SUNRISE AT
IWD WHERE WINDS ARE LIGHTER. ALTHOUGH THERE WL BE MORE CLDS ON MON
AFTN AND POSSIBLY EVEN A -SHRA LATE IN THE DAY INTO THE EVNG WITH
THE APRCH OF A DISTURBANCE IN THE PRESENCE OF DAYTIME HEATING...THE
LLVLS WL BE SUFFICIENTLY DRY TO ENSURE VFR WX EVEN IF A -SHRA
IMPACTS ANY OF THE SITES.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 AM EDT MON JUL 28 2014

NORTH TO NORTHWEST WINDS 15-20 KTS LINGER TODAY OVER MAINLY EASTERN
LK SUPERIOR DUE TO TIGHTER PRESSURE GRAIDENT REMAINING IN WAKE OF LOW
PRESSURE CROSSING THE MID-ATLANTIC STATES. HIGH PRESSURE WITH WINDS
LESS THAN 15 KTS EXPECTED THE REST OF THE WEEK. &&

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

$$

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





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