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 251731
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
131 PM EDT FRI JUL 25 2014

.UPDATE...
ISSUED AT 912 AM EDT FRI JUL 25 2014

ALTHOUGH INFLUX OF MSTR IN SW FLOW BTWN HI PRES IN THE MID ATLANTIC
STATES AND FALLING MSLP IN THE PLAINS ASSOCIATED WITH CLOSED H5 LO
MOVING INTO SASKATCHEWAN WL ALLOW SCT SHOWERS OVER WRN UPR MI THIS
MRNG TO SPREAD TO THE E THRU THE DAY...LOWERED THE CHC FOR TS GIVEN
HI STABILITY SHOWN ON THE 12Z INL AND ESPECIALLY THE GRB RAOBS AS
WELL AS RUC FCST SDNGS FOR EVEN IRONWOOD THRU 21Z.
&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT FRI JUL 25 2014

THERE IS CURRENTLY A SFC RIDGE OVER THE CWA EXTENDING HIGH PRESSURE
OVER THE OHIO VALLEY. THIS RIDGE WILL BE FIGHTING OFF AN APPROACHING
LOW PRESSURE SYSTEM THAT IS CURRENTLY OVER THE SRN PORTION OT THE
ALBERTA/SASKATCHEWAN BORDER. BETWEEN THESE TWO FEATURES IS A 500MB
RIDGE...THE AXIS OF WHICH IS OVER THE ERN DAKOTAS AND INTO MANITOBA.
A SHORTWAVE IS CURRENTLY OVER FAR WRN LAKE SUPERIOR AND WILL MOVE
ALONG THE MI/WI BORDER THIS MORNING. SOME SHOWERS HAVE DEVELOPED
ALONG AND AHEAD OF THE SHORTWAVE...BUT WITH DRY LOW LEVELS HAVE ONLY
SEEN ONE OR TWO SFC OBS WITH VERY LIGHT RAIN...ALTHOUGH VIS REMAINED
10SM AND CIGS WERE AROUND 10KFT WITH THE SHOWERS.

THE SFC RIDGE WILL WEAKEN SOME THROUGH THE DAY WHILE BECOMING MORE
CONFINED TO THE FAR ERN/NRN CWA. MOISTURE WILL INCREASE OVER THE WRN
CWA THROUGH THE DAY SLOWLY...ALLOWING FOR INCREASED CHANCES OF
PRECIP THROUGH THE DAY ADDITIONAL WEAK SHORTWAVE ENERGY MOVES
THROUGH WHILE WAA INCREASES. STILL DO NOT HAVE MORE THAN LOW END
CHANCE POPS. WITH THE LINGERING DRY AIR OVER THE E...KEEP THEM DRY
THROUGH MOST OF THE DAY.

THE CONTINUALLY WEAKENING RIDGE PUSHES COMPLETELY E OF THE CWA FRI
NIGHT AS SHORTWAVE ENERGY AND A SFC TROUGH MOVES INTO THE CENTRAL
CWA BY LATE IN THE NIGHT. MAINTAINED CHANCE POPS INTO FRI NIGHT.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 451 AM EDT FRI JUL 25 2014

A SOMEWHAT ACTIVE WEATHER PATTERN WILL BE IN PLACE ACROSS THE REGION
THROUGH THE WEEKEND...WITH A SIGNIFICANT COOLDOWN STARTING SUNDAY
AND EXTENDING INTO NEXT WEEK.

ON SATURDAY...THE FORECAST AREA WILL REMAIN UNDER ZONAL W-NW FLOW
ALOFT WITH THE LEFT EXIT REGION OF THE JET AND ASSOCIATED SHORT
WAVE EXITING TO THE EAST. ANY REMAINING SHOWER ACTIVITY FROM FRI
NIGHT SHOULD EXIT AS WELL AS DRY ADVECTION MOVES ACROSS THE AREA.
THIS WILL ALLOW FOR CLEARING SKIES WITH TEMPERATURES TO WARM INTO
THE MID-UPPER 70S ACROSS THE AREA. ALL THE NUMERICAL GUIDANCE
SUGGEST THAT INSTABILITY WILL INCREASE ACROSS THE EASTERN HALF OF
THE FORECAST AREA DURING THE AFTERNOON IN RESPONSE TO THE DIURNAL
HEATING. ALTHOUGH THE FORECAST CAPE VALUES OF 1000-2000 J/KG IS
LIKELY TOO HIGH DUE TO THE NORMAL HIGH BIAS OF SFC DEW
POINTS...THERE WILL LIKELY STILL BE INSTABILITY OF AT LEAST 1000
J/KG DURING THE LATE MORNING/AFTERNOON SIMPLY DUE TO THE STEEPER
LAPSE RATES ALOFT OF 6.5 C/KM. AS SUCH...HAVE OPTED TO MAINTAIN
CHANCE POPS ACROSS THE EASTERN LAKE BREEZE AREAS DURING THE
AFTERNOON HOURS ESPECIALLY WITH THE NAM AND GFS KEEPING THE LEFT
EXIT REGION OF THE JET AND ASSOCIATED WEAK Q-VECTOR CONVERGENCE IN
THIS AREA DURING THE AFTERNOON. THE BIG LIMITING FACTOR FOR MORE
WIDESPREAD CONVECTION WILL BE THE DRY AIR ALOFT...AND LACK OF
SIGNIFICANT LOW LEVEL FORCING OTHER THAN THE LAKE BREEZE ACTIVITY.
THIS AGREES WELL WITH THE HIGH RES NUMERICAL GUIDANCE THAT SUGGEST A
FEW STORMS ALONG THE LAKE BREEZE DURING THE DAY.

ON SATURDAY NIGHT INTO SUNDAY...THE UPPER LOW CURRENTLY OVER ALBERTA
WILL MOVE TOWARD THE AREA. MEANWHILE...THE UPPER LOW NE OF JAMES BAY
WILL RETROGRADE SLIGHTLY TO THE WEST AND SOUTH. THESE TWO FEATURES
WILL ALLOW FOR THE FRONT TO THE NORTH OF THE AREA TO MOVE ACROSS THE
REGION LATE SAT NIGHT INTO SUNDAY MORNING. AS THIS OCCURS...LOW
PRESSURE ASSOCIATED WITH THE UPPER LOW TO THE WEST WILL MOVE ALONG
THE FRONT ON SAT NIGHT INTO SUNDAY...TRACKING SOUTH OF THE AREA.
SHOWER AND ISOLATED STORMS WILL MOVE INTO THE AREA LATER SAT NIGHT
AHEAD OF THE UPPER LOW...THEN SPREAD ACROSS THE ENTIRE FORECAST AREA
ON SUNDAY. SUNDAY SHOULD END UP BEING A FAIRLY COOL AND DAMP DAY
WITH A BRISK /AT LEAST FOR SUMMER/ NORTH WIND. TEMPERATURES WILL
REMAIN FAIRLY STEADY IN THE 60S ACROSS THE AREA. IN FACT...IT WOULD
NOT BE SURPRISING IF TEMPS WILL FALL DURING THE DAY ESPECIALLY
CLOSER TO LAKE SUPERIOR AS 850MB TEMPS DROP TO 10C BY SUN EVENING.
THE GOOD NEWS IS THAT THE RAIN SHOULD RAPIDLY END LATE SUN AFTERNOON
INTO SUNDAY EVENING AS THE LOW MOVES EAST OF THE AREA. HOWEVER...BY
MONDAY MORNING 850MB TEMPS WILL DROP TO +6C WHICH WILL ALLOW FOR A
COOL NIGHT SUNDAY NIGHT. MONDAY WILL BE TRANQUIL AS WELL WITH STABLE
NORTH WINDS AND BUILDING HIGH PRESSURE ACROSS THE UPPER GREAT LAKES.

FOR THE TUE-THU TIME PERIOD...THE UPPER GREAT LAKES WILL REMAIN
BELOW NORMAL WITH THE DEEP TROUGH PERSISTING ACROSS THE EASTERN HALF
OF THE U.S. THROUGH THE PERIOD. THE UPPER LOW JUST EAST OF HUDSON
BAY WILL REMAIN FAIRLY STATIONARY THROUGH THE PERIOD. WEAK UPPER
LEVEL SHORT WAVES WILL ROTATE AROUND THE UPPER LOW AND ACROSS THE
AREA...WHICH WILL MAKE TIMING OF PRECIPITATION SOMEWHAT DIFFICULT.
HOWEVER...WITH THE COLD TEMPERATURES ALOFT COMBINED WITH FAIRLY
FREQUENT DISTURBANCES ALOFT...EXPECT THE BEST CHANCES FOR SHOWERS
AND STORMS TO BE DURING THE PEAK HEATING HOURS IN THE AFTERNOON AND
EARLY EVENING HOURS EACH DAY. OTHERWISE...TEMPERATURES WILL REMAIN
BELOW NORMAL THROUGH THE PERIOD.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 129 PM EDT FRI JUL 25 2014

WITH INFLUX OF MOISTER AIR IN LLVL SW FLOW AND APRCH OF AN UPPER
DISTURBANCE...EXPECT SHRA AND AREA OF MVFR CLDS NEAR IWD TO
OVERSPREAD CMX AND SAW BY THIS EVNG. WITH SOME DRYING ALF LATE TNGT
THAT WL END THE SHOWERS...EXPECT IFR CONDITIONS TO DVLP IN THE
PRESENCE OF DIURNAL COOLING. LIFR CONDITIONS ARE NOT OUT OF THE
QUESTION. THE ARRIVAL OF DRIER AIR AND DAYTIME WL RESULT IN
IMPROVEMENT TO VFR ON SAT. THIS PROCESS WL BE SLOWEST AT CMX WITH AN
UPSLOPE W WIND.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT FRI JUL 25 2014

EXPECT WINDS UNDER 15 KTS THRU SAT NIGHT WITH RELATIVELY WEAK PRES
GRADIENT DOMINATING THE UPPER LAKES. STRONGER N WINDS UP TO 20-25
KTS ARE POSSIBLE ON SUN INTO MON AS COOLER AIR INVADES THE AREA
UNDER TIGHTER GRADIENT BETWEEN HI PRES MOVING INTO THE NORTHERN
PLAINS AND LO PRES OVER THE SE GREAT LAKES. WINDS WILL DIMINISH ON
TUE AND BACK TOWARD THE W WITH CLOSER APPROACH OF HI PRES FROM THE
PLAINS.
&&

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

$$

UPDATE...KC
SHORT TERM...TITUS
LONG TERM...MRD
AVIATION...KC
MARINE...TITUS




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