Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KMQT 182032
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
432 PM EDT MON AUG 18 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 322 PM EDT MON AUG 18 2014

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAIRLY STRONG
SHRTWV OVER THE NRN PLAINS DRIFTING TO THE ESE INTO NW MN DOWNSTREAM
OF A RDG OVER WRN CANADA AND TOWARD A SHRTWV RDG STRETCHING FM
HUDSON BAY TOWARD THE SE GREAT LKS ON THE WRN FLANK OF A DEEP TROF
OVER THE CNDN MARITIMES. THERE IS ALSO A WEAKER SHRTWV MOVING E THRU
THE UPR LKS AHEAD OF THE MAIN DISTURBANCE APRCHG MN...AND THIS
FEATURE ALONG WITH ACCOMPANING AXIS OF GREATER H85 THETA E ADVCTN/A
FAIRLY MOIST 12Z GRB RAOB /KINX 36C AND PWAT 1.64 INCH OR ALMOST 175
PERCENT OF NORMAL/ HAS BEEN THE FOCUS FOR SOME SCT-NMRS SHOWERS
MAINLY OVER CENTRAL CWA TODAY. BUT QUITE A CONTRAST JUST TO THE E
WITH THE 12Z APX RAOB DISPLAYING A MUCH DRIER PROFILE...KINX -12C
AND PWAT 0.66 INCH OR ONLY 75 PERCENT OF NORMAL. THIS DRIER/STABLE
AIRMASS HAS SLOWED THE PROGRESS OF THE SHOWERS INTO THE AREA ARND
NEWBERRY SO FAR. THERE ARE MORE NMRS SHOWERS/A FEW TS MOVING INTO
WRN LK SUP CLOSER TO THE TRAILING SHRTWV. OTRW...QUITE A BIT OF CLD
COVER HAS LIMITED THE DIURNAL RISE OF TEMP AND DESTABILIZATION IN
THE ABSENCE OF STEEP LAPSE RATES SHOWN ON EVEN THE MOISTER 12Z GRB
RAOB...SO TS HAVE BEEN FEW AND FAR BTWN. BUT SOME HEAVY RAINS HAVE
FALLEN UNDER THE STRONGER SHOWERS WITH THE HIER PWAT/DEEPER MSTR.

MAIN FCST CONCERNS IN THE SHORT TERM ARE POPS RELATED TO THE TWO
DISTURBANCES THAT ARE MOVING THRU MN/THE UPR LKS.

LATE TODAY/TNGT...AS TROF OVER QUEBEC SLOWLY EXITS TO THE E...LEAD
SHRTWV MOVING THRU THE UPR LKS/ACCOMPANYING AXIS OF H85 THETA E
ADVCTN WL DRIFT TO THE E AND BRING SOME SHOWERS TO THE FAR ERN CWA
BY 00Z. ALTHOUGH THERE MAY BE ONLY SOME ISOLD/SCT SHOWERS OVER WRN
UPR MI WITH SOME H7-5 DRYING MOST OF TODAY...MORE NMRS SHOWERS/SOME
TS ASSOCIATED WITH THE STRONGER SHRTWV MOVING INTO MN WL ARRIVE OVER
THE FAR W ARND 00Z TOWARD AREA WHERE THE 12Z NAM/REGIONAL CNDN MODEL
SHOW HIER MUCAPE UP TO ABOUT 750 J/KG NEAR IWD. BUT SINCE THE MN
SHRTWV WL BE TENDING TO DIG ESEWD THRU THE NGT...THE 12Z NAM/
REGIONAL CNDN MODEL INDICATE THE MORE NMRS SHOWERS WL IMPACT WI
CLOSER TO MORE VIGOROUS H85-7 MSTR CNVGC/HIER MUCAPE IN THE 500-
1000J/KG THAT WL BE CONFINED TO WI. SO WL MAINTAIN THE HIEST LIKELY
POPS TOWARD THE WI BORDER... ALONG WITH THE TS CHANCES PER ABSENCE
OF FCST MUCAPE AOA 200 J/KG FARTHER N. BUT DEEP LYR QVECTOR CNVGC/
DEEP SATURATION ON FCST SDNGS ON THE CYC SIDE OF SHRTWV TRACK
JUSTIFIES AT LEAST 50-60 POPS OVER THE ENTIRE CWA EVEN IF THE BETTER
FORCING/INSTABILITY HOLD TO THE SW. EXPECT LTL DIURNAL TEMP DROP
WITH LOTS OF CLDS/LINGERING HIER PWAT IN THE 1.50-1.75 RANGE. ADDED
SOME PATCHY FOG...ESPECIALLY IN AREAS OVER THE CENTRAL THAT WL
EXPERIENCE UPSLOPE SE FLOW.

TUE...EXPECT CONTINUED SCT-NMRS SHOWERS AND A FEW TS AS THE SHRTWV/
SFC LO REFLECTION SLIDE ESEWD THRU NRN WI AND MAINTAINS DEEP MSTR...
CYC FLOW AND DEEP LYR QVECTOR CNVGC OVER UPR MI. FCST WL SHOW
DIMINISHING POPS IN THE AFTN OVER THE W WITH PASSAGE OF SHRTWV TO
THE E AND ARRIVAL OF SOME DNVA/DEEP LYR QVECTOR DVGC AFT 18Z. FOG IN
THE MRNG OVER MAINLY THE CENTRAL ZNS WL DSPT SLOWLY WITH DIURNAL
HEATING LIMITED BY EXTENSIVE CLD COVER.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 431 PM EDT MON AUG 18 2014

THE 500MB LOW CENTERED OVER UPPER MI AND LAKE SUPERIOR AT 00Z
WEDNESDAY WILL SHIFT ACROSS LAKE HURON WEDNESDAY NIGHT/THURSDAY
MORNING WITH A BRIEF RIDGE BUILDING ACROSS UPPER MI THURSDAY. THE
APEX OF THE RIDGE WILL SHIFT JUST TO OUR E THURSDAY NIGHT. A SIZABLE
TROUGH SET UP FROM FROM W AND CENTRAL CANADA THROUGH THE ENTIRE W
U.S. WEDNESDAY WILL SLOWLY SHIFT THE N CENTRAL U.S. FOR THE
WEEKEND...AND UPPER GREAT LAKES SUNDAY NIGHT/MONDAY.

AS FOR THE SFC FEATURES AND WX...THE EXITING SFC LOW OVER N LAKE MI
AT 00Z WEDNESDAY WILL LINGER THROUGH THE NIGHT BEFORE SHIFTING TO
LOWER MI THROUGH THE DAY WEDNESDAY. WITH WRAP AROUND/UPSLOPE
MOISTURE ACROSS THE AREA...EXPECT LIGHT SHOWERS TO LINGER THROUGH
MID DAY AT LEAST. THE BEST CHANCE OF THUNDERSTORMS WILL SINK SE WITH
THE SFC LOW.

IT LOOKS LIKE THE ONLY PERIOD OF MAINLY DRY WEATHER WILL BE LATE
WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING...DESPITE THE 500MB
RIDGE OVERHEAD THURSDAY THROUGH FRIDAY. THE LARGE HIGH PRESSURE OVER
QUEBEC...WITH A RIDGE EXTENDING OVER THE UPPER GREAT LAKES WILL EXIT
E ON FRIDAY. THERE STILL LOOKS TO BE PLENTY OF INCONSISTENCIES FOR
FRIDAY AFTERNOON ON. WILL CONTINUE TO RUN WITH A GENERAL CONSENSUS
FOR THIS PERIOD...WITH HAS AN ELONGATED SFC LOW FROM HUDSON BAY
THROUGH MN AND THE CENTRAL PLAINS AT 00Z SUNDAY. THE LOW WILL SLOWLY
SHIFT TO ONTARIO/FAR W LAKE SUPERIOR SATURDAY. THIS WOULD BRING WAA
TO THE AREA WITH HIGH TEMPS RETURNING TO NEAR NORMAL READINGS FRIDAY
AND SATURDAY. THE SFC TROUGH SHOULD BE OVER THE CWA SATURDAY
NIGHT/SUNDAY MORNING. HAVE SLOWLY DIMINISHING POPS FOR SUNDAY AND
MONDAY.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 123 PM EDT MON AUG 18 2014

ALTHOUGH THE SPECIFICS ARE FAR FROM CLEAR...EXPECT IFR CONDITIONS TO
PREDOMINATE THIS FCST PERIOD WITH DEEP MSTR/SCT TO AT TIMES NMRS
SHRA OVER THE UPR LKS ASSOCIATED WITH DISTURBANCE MOVING SLOWLY
ESEWD THRU MN. BEST CHC FOR THE LOWER LIFR...AND POSSIBLY VLIFR...
CONDITIONS WL BE LATER TNGT/EARLY TUE IN THE PRESENCE OF NOCTURNAL
COOLING WHEN THE TAF SITES EXPERIENCE UPSLOPE FLOW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 PM EDT MON AUG 18 2014

ADDED SOME FOG TO THE FORECAST THRU MUCH OF TUE OVER MAINLY THE
CENTRAL LAKE GIVEN ARRIVAL OF DEEPER MOISTURE AND EXPECTED AREA OF
LOWER TEMPERATURES NEAR THE LINGERING COOLEST DEEPER WATER.
OTHERWISE... EXPECT WINDS UNDER 20 KTS OVER THE NEXT WEEK AS A
RELATIVELY WEAK PRESSURE GRADIENT DOMINATES THE UPPER GREAT LAKES
ABOVE THE CHILLY WATERS OF LAKE SUPERIOR.
&&

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

$$

SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.