Area Forecast Discussion
Issued by NWS Gaylord, 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 KAPX 181959
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
359 PM EDT MON AUG 18 2014

.SYNOPSIS...
ISSUED AT 359 PM EDT MON AUG 18 2014

RAIN CHANCES WILL INCREASE FROM WEST TO EAST THIS EVENING AND
TONIGHT...AND CONTINUE THROUGH MIDWEEK...AS A SLOW MOVING LOW
PRESSURE SYSTEM SLIDES ACROSS THE REGION. THIS SYSTEM WILL BRING THE
POTENTIAL FOR LOCALIZED HEAVY RAINFALL OVER MUCH OF NORTHERN
MICHIGAN...ESPECIALLY TUESDAY AND TUESDAY NIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 359 PM EDT MON AUG 18 2014

...WIDESPREAD SHOWERS EXPECTED TONIGHT...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: 1017MB SURFACE HIGH WAS CENTERED ALONG
THE ONTARIO/QUEBEC BORDER...DIFFUSE/ELONGATED FRONTAL BOUNDARY
STRETCHED FROM LOW PRESSURE OVER NORTHWEST MINNESOTA...SOUTHEAST
ALONG THE UPPER/MIDDLE MISSISSIPPI VALLEY BEFORE TURNING EAST ALONG
THE OHIO RIVER.  WATER VAPOR IMAGERY SHOWS A COUPLE OF VORTICITY
CENTERS CROSSING THE NORTHERN HALF OF MINNESOTA.  WARM ADVECTION
INCREASING INTO MICHIGAN THIS AFTERNOON AS LOW LEVEL FLOW CONTINUES
TO VEER TO THE SOUTHWEST.  CLOUDS HAVE BEEN ON THE INCREASE FROM THE
WEST THIS AFTERNOON...AREA OF SHOWERS EXTENDS FROM EASTERN UPPER
BACK TO THE SOUTHWEST TOWARD GREEN BAY.

LEAD DYNAMIC PV ANOMALY CROSSING UPPER PORTIONS OF THE MISSISSIPPI
RIVER THIS AFTERNOON IS EXPECTED TO CROSS LOWER MICHIGAN TONIGHT...
WHILE ITS MORE SUBSTANTIAL COUNTERPART SPINS INTO NORTHWEST
WISCONSIN BY TUESDAY MORNING.  PRECIPITABLE WATER ABOVE 1.50 INCHES
ALREADY SPREADING ACROSS WESTERN UPPER AND TOWARD LAKE MICHIGAN THIS
AFTERNOON...AND THIS WILL ADVECT ACROSS THE REMAINDER OF THE STATE
TONIGHT.

PRIMARY FORECAST CONCERNS: PRECIPITATION EVOLUTION THROUGH TONIGHT.

TONIGHT...INITIAL AREAS OF SHOWERS IMPACTING THE NORTHWEST THIRD OF
THE FORECAST AREA WILL CONTINUE TO SLIDE THROUGH THE AREAS MAINLY
NORTH OF M-72 THROUGH LATE AFTERNOON/EARLY EVENING. BEYOND THAT...
PRIMARY FOCUS WILL BE ON UPSTREAM LEAD SHORT WAVE CROSSING THE
MINNESOTA/WISCONSIN BORDER WHICH IS STARTING TO KICK UP SOME
CONVECTION.  THE EXPECTATION IS THAT PRECIP WILL PROBABLY INCREASE
IN COVERAGE AHEAD OF THIS FEATURE AS IT SWINGS TOWARD LOWER MICHIGAN
LATER THIS EVENING...BRINGING MOST AREAS SHOWERS THROUGH MIDNIGHT.
DURING THE EARLY MORNING HOURS MAY SEE A DECREASE IN PRECIP COVERAGE
WITHIN SUBSIDENCE BEHIND THE LEAD UPPER WAVE...THOUGH RAIN SHOULD
NOT END COMPLETELY GIVEN PERSISTENT WARM ADVECTION AND DECREASING
STABILITY (INCREASING LOW LEVEL THETA-E COMBINED WITH COOL DYNAMIC
TROPOPAUSE TEMPERATURES).  POSSIBLE MCS DEVELOPMENT ACROSS THE UPPER
MIDWEST TONIGHT MAY ALSO COMPLICATE HOW THIS SCENARIO EVOLVES
OVERNIGHT...AN EAST/SOUTHEAST PROPAGATING CONVECTIVE COMPLEX MAY
REINFORCE THE IDEA OF A DECREASE IN PRECIPITATION COVERAGE DURING
THE PRE-DAWN HOURS.  BUT OUTSIDE OF TIMING INITIAL ARRIVAL OF RAIN
CHANCES NOT GOING TO GET TOO CUTE BEYOND THAT...CATEGORICAL POPS
PRETTY MUCH EVERYWHERE EXCEPT FOR THE FAR SOUTHEAST PORTION OF THE
FORECAST AREA.  OVERNIGHT LOWS MAINLY MID 50S-LOWER 60S.

&&

.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 359 PM EDT MON AUG 18 2014

TUESDAY THROUGH THURSDAY...VERY SLOW MOVING UPPER LEVEL LOW PRESSURE
WITH AMPLE MOISTURE AND A HISTORY OF PRODUCING GREATER THAN AN INCH
OF RAINFALL WITH LOCALLY HIGHER AMOUNTS WILL CONTINUE IT/S
PROGRESSION TOWARDS THE GREAT LAKES REGION TUESDAY AND WILL REMAIN
OVER THE FORECAST AREA THROUGH WEDNESDAY AND POSSIBLY EVEN INTO
EARLY THURSDAY. FORECAST SOUNDINGS SHOW "SKINNY CAPE" PROFILES WITH
NEARLY 1500 J/KG CAPE AT TIMES...PWATS IN EXCESS OF 1.75 INCHES...AND
VERY WEAK 0-6 KM STORM MOTION OF NO MORE THAN 10 KTS. IN
RESPONSE...ANY EMBEDDED CONVECTIVE ELEMENTS WILL PRODUCE VERY HEAVY
RAINFALL. AS THE PREVIOUS FORECASTER MENTIONED...MANY UPSTREAM
LOCATIONS RECEIVED OVER AN INCH IN UNDER 24 HOURS...WITH LOCALLY
HEAVIER AMOUNTS OF OVER 3...4...AND EVEN 5 INCHES OVER FAR EASTERN
NORTH DAKOTA. RIGHT NOW IT APPEARS AS IF THE SAME SCENARIO THAT
PLAYED OUT ABOUT A WEEK OR SO AGO WITH HEAVY RAIN EAST OF I-75 WILL
OCCUR AGAIN...BUT WITH EASTERN UPPER POSSIBLY GETTING IN ON THE
HEAVIER RAIN AMOUNTS AS WELL. THE TIMING OF WEAK ISENTROPIC ASCENT
AND VORTICITY MAX WITH SAID UPPER LEVEL LOW PRESSURE SYSTEM AND
AMPLE AMOUNTS OF MOISTURE WILL COMBINE TUESDAY TO PRODUCE THE
HEAVIEST AMOUNTS OF WIDESPREAD RAIN AND THEN A SECOND ROUND
WEDNESDAY AFTERNOON AS A SECONDARY TROUGH ALONG WITH A SHORTWAVE
COINCIDE OVER NORTHEAST LOWER. EXACT LOCATION OF UPPER LEVEL LOW
WILL GREATLY EFFECT HIGH TEMPERATURES TOMORROW AFTERNOON. LOOKING AT
UPSTREAM OBSERVATIONS...HIGH TEMPERATURES ONLY MADE IT INTO THE
UPPER 60S TO LOW 70S DUE EAST OF THE CENTER OF THE LOW...WHILE JUST
TO THE SOUTHEAST TEMPERATURES REACHED ALL THE WAY INTO THE UPPER 70S
AND EVEN NEAR 80 DEGREES. WITH CLOUDS AND PRECIPITATION FORECAST FOR
THE ENTIRE DAY TUESDAY...WILL SIDE WITH THE LOWER TEMPS. DAYTIME
TEMPERATURES WEDNESDAY APPEAR TO BE NEARLY IDENTICAL TO TUESDAY
AFTERNOON AND THURSDAY REACHING INTO THE MID TO UPPER 70S AS LOW
PRESSURE BEGINS TO DEPART TO THE EAST AND A THERMAL RIDGE STARTS TO
BUILT OVER THE GREAT LAKES REGION. LOW TEMPERATURES WILL BE IN THE
UPPER 50S TO LOW 60S THROUGHOUT THE PERIOD. OUR FAIRLY LIGHT WIND
REGIME CONTINUES THROUGH THE WORK WEEK AND INTO THE WEEKEND FROM A
SOUTHERLY DIRECTION FOR THE MAJORITY OF THE TIME.

FRIDAY THROUGH SUNDAY...MODELS ARE IN FAIRLY GOOD AGREEMENT OF A
THERMAL RIDGE BUILDING FROM THE GULF STATES TO THE GREAT LAKES
REGION. THERE WILL BE CHANCES OF AREAS OF CONVECTION RIDING THE
RIDGE INTO MICHIGAN...BUT TOO FAR OUT AT THIS TIME TO PIN POINT ANY
EXACT AREA. CLIMATOLOGY WOULD SUGGEST THE RIDGE WILL STAY FARTHER
SOUTH...WITH STORMS MISSING OUR FORECAST AREA ALL TOGETHER. WILL
WAIT AND SEE.

MONDAY...VERY LOW CONFIDENCE FOR THIS FAR OUT. MODELS ARE INDICATING
THAT THE AFOREMENTIONED RIDGE BEGINS TO BREAK DOWN AS AN AREA OF LOW
PRESSURE OVER WESTERN CANADA BEGINS TO MOVE INTO THE HUDSON BAY
AREA...DRAGGING A COLD FRONT THROUGH THE GREAT LAKES REGION.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 359 PM EDT MON AUG 18 2014

VFR CONDITIONS WILL GIVE WAY TO PERIODS OF MVFR OR BRIEF IFR
CONDITIONS WITH RAIN SHOWERS THAT WILL BE MOVING INTO NORTHWEST
LOWER AFTER 20Z. PRECIPITATION THREAT IS EXPECTED TO LINGER
THROUGH THE NIGHT AND INTO TUESDAY.

&&

.MARINE...
ISSUED AT 359 PM EDT MON AUG 18 2014

SMALL AREA OF LOW PRESSURE WILL INTENSIFY A LITTLE AS IT SLIDES
INTO WISCONSIN OVERNIGHT...THEN SLOWLY INCH ITS WAY ACROSS
MICHIGAN THROUGH MIDWEEK. WINDS ARE EXPECTED TO PICK UP FROM THE
SOUTH AND SOUTHEAST TONIGHT INTO TUESDAY...WIND SPEEDS SHOULD
REMAIN BELOW SMALL CRAFT CRITERIA THOUGH WAVES MAY START TO GET A
BIT CHOPPY ESPECIALLY ON NORTHERN LAKE HURON BY TUESDAY
AFTERNOON/TUESDAY NIGHT GIVEN LONG FETCH SOUTHEAST FLOW. WINDS
WILL DIMINISH AND BECOME MORE VARIABLE IN DIRECTION TUESDAY
NIGHT/WEDNESDAY WITH SURFACE LOW CROSSING THE UPPER LAKES (MORE
WEST/NORTHWEST WINDS ON LAKE MICHIGAN WITH STILL SOUTHEAST WINDS
ON LAKE HURON/WHITEFISH BAY).

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.

&&

$$

SYNOPSIS...MG
SHORT TERM...JPB
LONG TERM...TL
MARINE...JPB





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