372
FXUS63 KDTX 230958
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
558 AM EDT FRI AUG 23 2019
AVIATION
HIGH PRESSURE BUILDING INTO THE REGION WILL RESULT IN VFR CONDITIONS
THROUGH THE TAF PERIOD. COULD BE SOME SUB 5KFT CIGS POSSIBLE THIS
AFTERNOON AS DIURNAL CU FIELD DEVELOPS WITH THE AID OF NORTHEASTERLY
FLOW OFF THE LAKES PUSHING LOW LEVEL MOISTURE ACROSS THE AREA.
OVERALL THE SOUNDING LOOKS VERY DRY ABOVE 7KFT THUS DEEP MIXING
SHOULD ERODE THE CLOUD FIELD EASILY THIS EVENING. WINDS WILL REMAIN
NORTH/NORTHEAST WITH SPEEDS TO ABOUT 10 KNOTS IN BEST MIXING THIS
AFTERNOON.
DTW THRESHOLD PROBABILITIES
* MEDIUM FOR CIGS AOB 5KFT FOR A PERIOD OF TIME FRIDAY AFTERNOON.
PREV DISCUSSION
ISSUED AT 402 AM EDT FRI AUG 23 2019
DISCUSSION...
CONTINUED INFLUENCE OF LARGER SCALE HIGH PRESSURE STARTS THE DAY
ACROSS LOWER MICHIGAN BUT NOT WITHOUT SOME INTERACTION FROM THE
GREAT LAKES THAT BECOMES MORE EVIDENT DURING THE MORNING. SURFACE
AND MODEL ANALYSIS FIELDS SUGGEST A HYBRID BACKDOOR FRONT/AGGREGATE
TROUGH ACROSS SUPERIOR AND NORTHERN HURON THAT MARKS A SLIGHT
REINFORCEMENT OF COOL AIR. CLOUDS ALONG AND NORTH OF THE SURFACE
TROUGH EXTEND WELL NORTH INTO ONTARIO AND ARE MORE OF THE MID LEVEL
VARIETY SUPPORTED BY THE TROUGH AXIS AROUND 500 MB. THIS TROUGH AXIS
PIVOTS SOUTHEASTWARD DURING THE MORNING AND PULLS THE SUPERIOR/HURON
SURFACE TROUGH SOUTHWARD INTO SOUTHERN LAKE HURON AND THUMB REGION.
THE UPSTREAM CLOUDS THEN REPRESENT ADEQUATE MOISTURE FOR SCATTERED
SHOWERS DUE TO INSTABILITY OVER THE WARM LAKE WATER AND FROM DAYTIME
HEATING OVER THE LAND BY LATE MORNING THROUGH AFTERNOON. HI RES
MODEL SOLUTIONS HELP IDENTIFY THE AFFECTED LAND AREA LIMITED TO THE
THUMB REGION BEFORE SHOWERS DISSIPATE TOWARD EVENING. THIS LEAVES
ANOTHER NICE DAY ACROSS THE REST OF SE MICHIGAN WITH SOME POCKETS OF
MID CLOUDS DURING THE MORNING GIVING WAY TO CUMULUS THIS AFTERNOON
ALONG WITH A COMPONENT OF CLOUDS MOVING SOUTHWARD FROM THE THUMB.
GUIDANCE TEMPERATURE PROJECTIONS REMAIN ON THE LOW SIDE OF NORMAL
VALUES THAT ARE IN THE UPPER 70S TO AROUND 80 FOR HIGHS AND IN THE
UPPER 50S TO AROUND 60 FOR LOWS TODAY THROUGH THIS WEEKEND.
ANY REMNANT OF THE SURFACE TROUGH FILLS AND RELEASES INLAND IN A
HYBRID LAKE BREEZE FASHION WITH THE LOSS OF DAYTIME HEATING DURING
THE EVENING. A REINFORCEMENT OF SLIGHTLY MODIFIED BUT STILL COOLER
AIR THEN WASHES OVER THE REGION DURING THE NIGHT ON LIGHT BUT STEADY
NE WIND THAT IS SUPPLIED BY HIGH PRESSURE STRENGTHENING OVER
NORTHERN ONTARIO. BOTH THE SURFACE HIGH AND RIDGE ALOFT DRIFT ACROSS
THE GREAT LAKES AND COMBINE FOR IDEAL LATE SUMMER WEATHER DURING THE
WEEKEND. TEMPERATURES REMAIN SLIGHTLY BELOW NORMAL SATURDAY AND THEN
MODERATE SLIGHTLY BY SUNDAY.
PROSPECTS FOR RAIN INCREASE MONDAY THROUGH THE EARLY WEEK AS THE
UPPER LEVEL BLOCKING PATTERN SLOWLY MATURES. THE CURRENT UPPER LEVEL
LOW AND TROUGH OVER THE ROCKIES MAKE IT INTO THE PLAINS BY MONDAY
AND LATCH ON TO THE FRONT STALLED NEAR THE GULF COAST. THAT LEAVES
LITTLE DOUBT ABOUT THE MOISTURE SUPPLY AS THE LEAD WAVE MOVES INTO
THE GREAT LAKES AND ACROSS SE MICHIGAN MONDAY AFTERNOON AND NIGHT.
UNSETTLED WEATHER CONTINUES THROUGH TUESDAY AS A STRONG PACIFIC COLD
FRONT SURGES ACROSS THE REGION. GLOBAL MODEL SOLUTIONS PROJECT
DEVELOPMENT OF A LARGE AND STRONG LOW PRESSURE SYSTEM OVER CENTRAL
CANADA AND THE NORTHERN PLAINS WHICH LIKELY HAS HIGH PREDICTABILITY
OVERALL BUT STILL WITH TIMING QUESTIONS ON THE FRONTAL PASSAGE
ACROSS SE MICHIGAN. THUNDERSTORM POTENTIAL WILL BE DEPENDENT ON
REFINEMENT OF THIS TIMING TUESDAY INTO TUESDAY NIGHT.
MARINE...
CANADIAN HIGH PRESSURE WILL BECOME CENTERED OVER THE NORTHERN GREAT
LAKES TODAY BEFORE DEPARTING TO EASTERN CANADA OVER THE WEEKEND.
THIS SYSTEM WILL INFLUENCE THE REGION THROUGH THE END OF THE
WEEKEND. A WEAKENING GRADIENT WILL ATTEMPT TO KEEP WINDS DOWN BUT
LIGHT TO MODEST NORTHERLY WINDS WILL PERSIST THROUGH THIS EVENING AS
COLD AIR ADVECTION PRODUCES UNSTABLE CONDITIONS. WINDS AND WAVES
SHOULD STAY JUST BELOW SMALL CRAFT CRITERIA. THIS DEVELOPING
INSTABILITY WILL ALSO SUPPORT A CHANCE FOR WATERSPOUTS TODAY.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....DRK
DISCUSSION...BT
MARINE.......DRK
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