021
FXUS62 KCHS 172049
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
349 PM EST SUN NOV 17 2024
SYNOPSIS
HIGH PRESSURE WILL PREVAIL UNTIL A STRONG COLD FRONT MOVES
THROUGH MID WEEK. CANADIAN HIGH PRESSURE WILL BUILD ACROSS THE
AREA THURSDAY INTO SUNDAY.
NEAR TERM /UNTIL 6 AM MONDAY MORNING/
AFTERNOON COMPOSITE ANALYSIS REVEALS A STOUT UPPER LEVEL HIGH
ACROSS THE FLORIDA PENINSULA AND RIDGING EXTENDING UP ALONG THE
EAST COAST INTO NEW ENGLAND. SURFACE HIGH PRESSURE IS SITUATED
PRETTY MUCH OVER THE FORECAST AREA PROVIDING ANOTHER GREAT
WEATHER DAY, ALTHOUGH WITH SOME THICKER HIGH LEVEL CIRRUS
PASSING THROUGH THE REGION OVER TOP THE UPPER RIDGE.
TONIGHT: DRY HIGH PRESSURE WILL REMAIN CENTERED NEARLY RIGHT ON
TOP OF THE FORECAST AREA, AND ANOTHER VERY QUIET NIGHT IS ON
TAP. THIN CIRRUS WILL CONTINUE TO MOVE THROUGH, KEEPING SKIES
FROM BEING COMPLETELY CLEAR. HOWEVER, WE SHOULD AGAIN SEE CALM
WINDS AND GOOD RADIATIONAL COOLING CONDITIONS. LOWS WON'T BE
QUITE AS CHILLY AS THE NIGHT BEFORE, BUT WE SHOULD STILL SEE
LOWER TO MIDDLE 40S AWAY FROM THE IMMEDIATE COAST. THERE COULD
AGAIN BE SOME SHALLOW GROUND FOG OR STEAM FOG OFF THE LAKES/
RIVERS, WITH FOG PROBABILITIES FAVORING SOUTHEAST GEORGIA.
PATCHY FOG HAS BEEN ADDED TO PORTIONS OF THE FORECAST AREA.
SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/
MONDAY: STRONG HIGH PRESSURE RIDGING ALOFT, CENTERED NEAR THE
FLORIDA KEYS WILL EXTEND ACROSS THE LOCAL COUTNIES. SURFACE HIGH
PRESSURE CENTERED DIRECTLY OVERHEAD TO START THE DAY WILL PULL JUST
OFFSHORE FOR THE AFTERNOON. THE RETURN FLOW AROUND THE HIGH WILL
ALLOW FOR A WARMER DAY AFTER THE COLD START. HIGH TEMPERATURES WERE
DERIVED FROM A BLEND OF THE 1000-850 MB THICKNESS, MOS, AND NBM
GUIDANCE. THIS RESULTS IN HIGHS IN THE MIDDLE 70S AWAY FROM THE
COOLER BEACHES.
MONDAY NIGHT: THE CORE OF THE SURFACE HIGH REMAINS OVER THE OCEAN,
BUT STRETCHES BACK ACROSS THE IMMEDIATE VICINITY. FURTHER UPSTREAM,
A DEEP LOW MOVES FROM KANSAS AND NEBRASKA TO MINNESOTA, WHILE A MUCH
WEAKER LOW ASSOCIATED WITH SOME REMNANT ENERGY FROM SARA FORMS NEAR
THE MOUTH OF THE MISSISSIPPI RIVER. INCREASING HIGH LEVEL CLOUDS IN
ADVANCE OF THESE SYSTEMS, AND A SOUTHWEST SYNOPTIC FLOW WILL PROMOTE
A WARMER NIGHT THAN RECENTLY.
TUESDAY AND TUESDAY NIGHT: CONSIDERABLE MOISTURE WILL STREAM OUT OF
THE GULF OF MEXICO IN ADVANCE OF WEAK LOW PRESSURE ADVANCING
SLOWLY EASTWARD ALONG THE NORTHERN GULF COAST, AND ITS ASSOCIATED
FRONTAL SYSTEM. THAT SYSTEM IS THE RESULT OF SHORT WAVE ENERGY ALOFT
(PROBABLY AT LEAST IN SOME FORM FROM SARA) AND THE UPPER JET
STRETCHING FROM TEXAS TO THE MID-ATLANTIC REGION. SIMILAR TO WHAT
WE SAW YESTERDAY, THERE ARE INDICATIONS THAT AN MCS THAT MIGHT
FORM TO THE SOUTH, COULD CUT OFF THE BETTER FEED OF MOISTURE ACROSS
OUR AREA. AS SUCH WE HAVE NO MORE THAN ISOLATED POPS TUESDAY, AND
GENERALLY SCATTERED POPS TUESDAY NIGHT. QPF AT THIS POINT IS
MAINLY 1/4 INCH OR LESS. WARM ADVECTION WILL ALLOW FOR HIGHS AT
LEAST INTO THE MIDDLE 70S AWAY FROM COAST TUESDAY, WHILE LOWS
TUESDAY NIGHT WILL BE AROUND 5-10F WARMER THEN MONDAY NIGHT.
WEDNESDAY: THE FRONTAL SYSTEM TO OUR SOUTH LOOKS TO REMAIN SOUTH, OR
BECOMES ABSORBED INTO A STRONG COLD FRONT THAT PUSHES OFFSHORE IN
THE AFTERNOON. RAIN CHANCES WILL COME TO AN END WITH THE FRONTAL
PASSAGE, AND WITH THE COLD ADVECTION LAGGING FURTHER BEHIND, IT'LL
AGAIN BE A WARM DAY WITHIN A WESTERLY DOWNSLOPE FLOW. MIGHT EVEN SEE
SOME UPPER 70S IF THE RAINS END QUICK ENOUGH.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
A BROAD AND DEEP LONG WAVE TROUGH WILL PREVAIL OVER THE EASTERN
STATES THURSDAY AND FRIDAY, THEN GIVES WAY TO ZONAL FLOW ALOFT AS
THE TROUGH LIFTS AWAY TO THE NORTHEAST OVER THE WEEKEND. DEEP
SURFACE LOW PRESSURE IN THE NORTHEAST STATES WILL FOLLOW ALONG, AS
COLDER CANADIAN HIGH PRESSURE STEADILY BUILDS IN. THIS WILL SUPPLY
THE REGION WITH A DRY AND MUCH COLDER AIR MASS THROUGH THE LONG TERM
PERIOD. HIGHS WILL BE AROUND 8-10F BELOW CLIMO, WHILE NIGHT TIME
LOWS WILL DROP INTO THE 30S ACROSS MANY INLAND AREAS. THE BEST NIGHT
FOR ANY CONCERNS OF FROST LOOKS TO BE SATURDAY NIGHT WHEN WIND
FIELDS ARE THE WEAKEST. CONDITIONS ARE ALSO FAVORABLE FOR A LAKE
WIND ADVISORY ON LAKE MOULTRIE WEDNESDAY NIGHT THROUGH FRIDAY AS
THE COLDER AIR MASS OVERSPREADS THE REGION ALLOWING FOR CONSIDERABLE
MIXING.
AVIATION /20Z SUNDAY THROUGH FRIDAY/
VFR CONDITIONS WILL PREVAIL AT KCHS, KJZI, AND KSAV THROUGH 18Z
MONDAY.
EXTENDED AVIATION OUTLOOK: PREVAILING VFR. BRIEF FLIGHT
RESTRICTIONS POSSIBLE IN SHOWERS TUESDAY NIGHT INTO WEDNESDAY IN
ADVANCE OF A COLD FRONT. GUSTY WEST WINDS ARE EXPECTED THURSDAY
AND FRIDAY.
MARINE
TONIGHT: HIGH PRESSURE OVERHEAD WILL MAINTAIN TRANQUIL
CONDITIONS ACROSS THE MARINE WATERS WITH WINDS MOSTLY AROUND 5
KNOTS, AND CERTAINLY NOT MORE THAN 5-10 KNOTS. SEAS WILL
CONTINUE TO DIMINISH, AND WILL MOSTLY AVERAGE AROUND 2 FEET FOR
THE NEARSHORE WATERS AND 2-3 FEET FOR THE OUTER WATERS.
MONDAY AND MONDAY NIGHT: HIGH PRESSURE WILL PREVAIL, KEEPING
CONDITIONS RATHER TRANQUIL ACROSS THE COASTAL WATERS. WINDS ARE NO
MORE THAN 5 OR 10 KT, WITH SEAS JUST 2 OR 3 FEET AT BEST.
TUESDAY AND TUESDAY NIGHT: THERE'S A BIT OF AN UPTICK IN WINDS AND
MAYBE SEAS AS A FRONTAL SYSTEM MOVES THROUGH THE NORTHERN GULF COAST
REGION, AND THE HIGH PULLS OFF TO THE SOUTHEAST. BUT STILL NOTHING
MORE THAN 10 OR 15 KT AND 3 FOOT SEAS. SCATTERED SHOWERS WILL MOVE
IN TUESDAY NIGHT IN ADVANCE OF THE FRONTAL SYSTEM.
WEDNESDAY THROUGH FRIDAY NIGHT: A STRONG COLD FRONT WILL PASS INTO
THE WATERS LATER WEDNESDAY, AND IS FOLLOWED BY CANADIAN HIGH
PRESSURE THEREAFTER. COLD ADVECTION WILL MIX PLENTY OF THE 30 OR 35
KT GEOSTROPHIC WINDS AT 1000 MB, RESULTING IN SOLID SMALL CRAFT
ADVISORIES, AND EVENTUALLY MAYBE EVEN GALES.
TIDES/COASTAL FLOODING
ELEVATED TIDES WILL CONTINUE EARLY THIS WEEK. AT LEAST MINOR
COASTAL FLOODING IS EXPECTED ALONG THE CHARLESTON AND COASTAL
COLLETON COUNTY COASTS WITH THE MONDAY MORNING HIGH TIDE. TIDES WILL
BE CLOSE TO MINOR FLOODING LEVELS TUESDAY MORNING, BUT THE LATEST
FORECAST KEEPS IT JUST SHY. FROM BEAUFORT SOUTH TO COASTAL MCINTOSH,
INCLUDING THE FORT PULASKI AREA, TIDE LEVELS ARE CURRENTLY FORECAST
TO STAY BELOW MINOR FLOOD CRITERIA.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
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