736
FXUS63 KAPX 130819
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
419 AM EDT TUE AUG 13 2013
.SYNOPSIS...
ISSUED AT 324 AM EDT TUE AUG 13 2013
HIGH PRESSURE WORKS ITS WAY DOWN INTO THE GREAT LAKES TODAY AND
CAMPS OUT FOR SEVERAL DAYS. RAINFALL CHANCES WILL BE ALMOST
NIL...WITH A HEALTHY DOSE OF BEAUTIFUL SUMMER WEATHER...THAT WILL
WARM INTO THE MIDDLE AND UPPER 70S FOR THE LATTER HALF OF THE WORK
WEEK AND UPCOMING WEEKEND.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 324 AM EDT TUE AUG 13 2013
RATHER ENERGETIC...ALBEIT SOMEWHAT MOISTURE STARVED...PATTERN
ESTABLISHED ACROSS THE GREAT LAKES AT THIS EARLY HOUR. YESTERDAY'S
SHOWER AND THUNDERSTORM PRODUCING WAVE HAS EXITED WELL TO OUR
EAST...WITH ANOTHER WAVE QUICK ON ITS HEELS DIVING SOUTHEAST ACROSS
LAKE SUPERIOR. NOT A WHOLE LOT OF SENSIBLE WEATHER GOING ON WITH
THIS SECONDARY WAVE...WITH ANY APPRECIABLE MOISTURE STRIPPED OUT BY
YESTERDAYS SYSTEM. THAT SAID...THIS WAVE HAS PLENTY OF UNSEASONABLY
COLD AIR ASSOCIATED WITH IT...WITH HIGH RES RAP GUIDANCE SHOWING H8
TEMPERATURES IN THE LOWER SINGLE DIGITS OVER EASTERN LAKE
SUPERIOR...WITH -20C H5 READINGS MOVING SOUTH ACROSS THE BIG LAKE AS
WELL. PLENTY OF COLD ENOUGH AIR TO DRUM UP A LAKE RESPONSE...WITH
WELL EVIDENT STCU STREAMERS DEVELOPING OVER NORTHERN LAKE
MICHIGAN...HURON...AND FAR EASTERN LAKE SUPERIOR. MOISTURE
PROFILES/DEPTH NOT QUITE DEEP ENOUGH TO GENERATE ANY SHOWER ACTIVITY
PER RADAR AND OBSERVATION. SUPPOSE A SPRINKLE MAY BE FALLING OUT OF
THIS CLOUD DECK...JUST TOO LIGHT TO BE PICKED UP OUR RADAR. WHILE
SURFACE CAA NOT QUITE AS IMPRESSIVE AS WHAT IS HAPPENING
OVERHEAD...STILL QUITE CHILLY OUT THERE WITH CURRENT READINGS MAINLY
IN THE UPPER 40S AND 50S. SHORT TERM FORECAST CONCERNS THROUGH
TONIGHT CENTER ON TEMPERATURE/CLOUD TRENDS AS WELL AS SHOWER
POTENTIAL AS UPSTREAM WAVE AND ATTENDANT COLD CORE PUSH THROUGH THE
REGION.
KNOCKING THE EASY PORTION OF THE FORECAST OUT OF THE WAY...
TEMPERATURES TODAY AND TONIGHT WILL RUN SEVERAL DEGREES BELOW
NORMAL. CULPRIT IS AFOREMENTIONED COLD CORE SYSTEM AND INTENSIFYING
LOW LEVEL CAA WITHIN SOMEWHAT GUSTY NORTHWEST SURFACE WINDS. HIGHS
TODAY WILL STRUGGLE THROUGH THE MIDDLE AND UPPER 60S...A GOOD 10
DEGREES OR SO BELOW NORMAL (AT LEAST THE WINDS WON'T MAKE IT FEEL
ANY COLDER...OH...NEVER MIND). AS FOR RAIN POTENTIAL...MAIN WAVE AND
UPWARD QG RESPONSE MOVES THROUGH THIS MORNING...LEAVING OVERHEAD
COLD POOL AND POSSIBLE LAKE CONTRIBUTIONS FOR SHOWER GENERATION. NOT
A FAN OF SEEING MUCH WITH THE LATTER AS WE HEAD THROUGH THE DAY
GIVEN STRONG DIURNAL DISRUPTION AND DRYING LOW LEVELS. LAKES LIKELY
WILL ADD AT LEAST SOME BOUNDARY LAYER MOISTURE...PERHAPS HELPING THE
OVERHEAD COLD POOL KICK OFF A FEW MOSTLY INTERIOR SHOWERS. H5
TEMPERATURES NEAR -20C DEFINITELY SUPPORTS THIS NOTION.
INTERESTINGLY...BOTH NAM-WRF AND GFS BUFFER SOUNDINGS SHOW A
RELATIVE WARN NOSE CENTERED AROUND H7...WITH SURFACE BASED PARCELS
JUST BARELY SCRAPPING BY THIS LEVEL. REALLY LIKE LOOK OF INHERITED
FORECAST FEATURING LOW END SHOWER POTENTIAL...ESPECIALLY ACROSS
CLIMATOLOGICALLY FAVORED ARES OF NORTHEAST LOWER AND PARTS OF EASTERN
UPPER MICHIGAN. WILL MAKE SOME MINOR CHANGES...BUT GIST OF FORECAST
WILL ESSENTIALLY REMAIN UNCHANGED. PLENTY OF DIURNALLY DRIVEN
CU/STCU EXPECTED OTHERWISE...LEADING TO A PARTLY TO MOSTLY CLOUDY
DAY. YUP...GOING TO FEEL A LOT LIKE THE MIDDLE OF SEPTEMBER!
STRONG CANADIAN HIGH PRESSURE CONTINUES TO BUILD INTO THE WESTERN
GREAT LAKES TONIGHT...WITH MID LEVEL COLD POOL AND DEEPEST TROUGHING
PUSHING OFF TO OUR EAST. THIS SHOULD END ANY LINGERING SHOWER THREAT
QUICKLY LATER THIS AFTERNOON...LEADING TO A DRY OVERNIGHT. CLOUD AND
TEMPERATURE TRENDS MUCH MORE FORMIDABLE CHALLENGES. GUIDANCE BACKING
AWAY FROM ROTATING EASTERN LAKES CLOUD DECK BACK WEST INTO OUR
AREA...AND FEEL THE NAM IS MUCH TOO AGGRESSIVE KICKING OFF STRATUS
ACROSS THE HIGHLANDS GIVING FLOW PATTERN AND GIVING JUST OFF THE
DECK VERY DRY AIR. WILL HEDGE OPTIMISTICALLY (YUP...I SAID IT) AND
GO MAINLY CLEAR THROUGH MUCH OF THE OVERNIGHT. UNSEASONABLY COLD
AIRMASS ARGUES FOR SOME VERY CHILLY READINGS...ESPECIALLY IF CLEAR
SKIES COME TO FRUITION. HOWEVER...NOT ENTIRELY SOLD ON JUST HOW COLD
READINGS BECOME TONIGHT...WITH CENTER OF HIGH PRESSURE REMAINING
JUST UPSTREAM. WILL NUDGE INHERITED LOWS DOWN A TOUCH...INTRODUCING
NEAR 40 DEGREE READINGS IN THE TRADITIONAL ICE BOX LOCATIONS
(GRAYLING...ATLANTA...AND SUCH). IF FULL DECOUPLING IS
REALIZED...THESE READINGS WILL LIKELY BE A TOUCH TO "WARM"...WITH
SOME MID AND UPPER 30S DEFINITELY PLAUSIBLE. EITHER WAY...ANOTHER
CHILLY MID AUGUST NIGHT FOR THE NORTH WOODS.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 324 AM EDT TUE AUG 13 2013
A MOISTURE-STARVED NORTHWEST FLOW ALOFT WILL GRADUALLY BECOME MORE
ZONAL LATER THIS WEEK AND INTO THE UPCOMING WEEKEND...WITH COOLISH
TEMPERATURES WARMING OVER THIS TIME. THERE IS ALMOST NO CHANCE FOR
RAINFALL FOR THE NEXT SEVERAL DAYS...AT LEAST ANY CHANCE THAT
WOULD BE WORTHY OF BEING INTRODUCED INTO THE FORECAST RIGHT NOW.
WEDNESDAY THROUGH FRIDAY...A STOUT NW FLOW ALOFT WILL LOOSEN UP
OVER THIS TIME...WITH SLOWLY RISING HEIGHTS...AS RIDGING FROM THE
ROCKIES JUST SLOWLY BLEEDS INTO THE HEART OF THE COUNTRY. THERE IS
A SERIOUS LACK OF MOISTURE OVER THIS TIME...WITH NO CHANCES FOR
RAIN CURRENTLY IN THE FORECAST...OR EVEN CONSIDERED INTO THE
FORECAST. THAT SAID...THERE IS A DECENT SHORTWAVE DROPPING IN
ACROSS EASTERN ONTARIO/QUEBEC ON THURSDAY...THAT WILL TRY AND LAY
OUT A STRIP OF "DEEPER" MOISTURE ALONG SFC TROUGH/COLD FRONT IN
EASTERN UPPER. SOMETHING TO KEEP AN EYE ON. TEMPERATURES IN THE
MIDDLE AND UPPER 60S WEDNESDAY WILL WARM INTO THE 70S FOR THURSDAY
AND FRIDAY. THE MAIN WEATHER STORY MAY BE THE DRYNESS OF THE BL
OVER THIS TIME...WITH MODELS MORE THAN LIKELY UNDER-FORECASTING THE
MIXING THAT WILL TAKE PLACE. FCST SOUNDINGS SUGGEST +10F DECREASES
IN SFC TDS FROM THE MOS NUMBERS. IT'LL BE A DRY LOW LEVEL AIR
MASS...BUT WITH WINDS GENERALLY 10KTS OR LESS...FIRE WEATHER
CONCERNS ARE MINIMAL.
SATURDAY THROUGH MONDAY...SFC HIGH PRESSURE WILL BE OVER THE EAST
COAST...BUT TRAILING BACK WESTWARD AND INTO THE GREAT LAKES. THE
PATTERN IS VERY SLOW TO MORPH INTO A WEAK ZONAL FLOW. TEMPERATURES
WILL CREEP UP INTO THE UPPER 70S AND LOWER 80S OVER THIS
TIME...AND AGAIN...WITH VERY MINIMAL CHANCES FOR PRECIPITATION.
THERE IS A SUGGESTION THAT A PIECE OF SHORTWAVE ENERGY GETS CUT OFF
TO OUR SW...WHICH COULD TECHNICALLY ROAM UP OUR WAY...BUT THE
BETTER CHANCE FOR RAIN MAY EVENTUALLY BE WITH A SHORTWAVE AND SFC
TROUGH/THETA-E BUMP MORE TOWARD TUESDAY. MAY EVEN STILL BE LOOKING
AT CONTINUED LOW AFTERNOON DEW POINTS...MUCH LOWER THAN MODEL
NUMBERS.
VERY BEAUTIFUL WEATHER IN STORE FOR US.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1157 PM EDT MON AUG 12 2013
MVFR CIGS AT TIMES TONIGHT/TUESDAY MORNING. GUSTY NNW WINDS
TUESDAY.
AUTUMN-LIKE WX IN STORE...AS UNSEASONABLY COOL AIR ENTERS THE
REGION BEHIND A DEPARTING COLD FRONT. COOL AIR MOVING OVER THE
WARM GREAT LAKES WILL RESULT IN LAKE-INDUCED CLOUD COVER TONIGHT
INTO TUESDAY. MVFR CIGS EXPECTED AT ALL TAF SITES...IMPROVING TO
VFR DURING THE DAY ON TUESDAY. COULD BE A TOUCH OF DRIZZLE/-RA...
ESPECIALLY TVC/APN...BUT SMALL RISK IS NOT WORTH INCLUDING IN THE
TAFS AT THIS TIME.
NNW-ERLY BREEZE TONIGHT AND TUESDAY...RATHER GUSTY BY MIDDAY
TUESDAY.
&&
.MARINE...
ISSUED AT 324 AM EDT TUE AUG 13 2013
MARINE...CONDITIONS MUCH MORE REMINISCENT OF EARLY FALL THAN
AUGUST...WITH CANADIAN HIGH PRESSURE BRINGING A BLAST OF
UNSEASONABLY CHILLY AIR TO THE BIG WATERS. RATHER TIGHT PRESSURE
GRADIENT AND INCREASING OVER-WATER INSTABILITY WILL EASILY ALLOW
GOOD DEEP LAYER MIXING OVER THE WATERS...PRODUCING GUSTY NORTHWEST
WINDS. LOOKS LIKE TWO CORRIDORS OF STRONGER WIND GUSTS...ONE THROUGH
EARLY THIS MORNING...WITH ANOTHER AS WE HEAD THROUGH THIS AFTERNOON
AND EARLY EVENING. PLETHORA OF SCA CONDITIONS EXPECTED...A
COMBINATION OF GUSTY WINDS AND INCREASINGLY CHOPPY CONDITIONS. WINDS
BEGIN TO DIE OFF SOME HEADING INTO LATER TONIGHT AND WEDNESDAY AS
THEY SLOWLY BACK MORE WESTERLY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ323-342-
344>346.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ321.
&&
$$
SYNOPSIS...SD
SHORT TERM...MB
LONG TERM...SD
AVIATION...JZ
MARINE...MB