textproduct: Charleston

WHAT HAS CHANGED

Lowered dew points/RH for today across much of the area.

KEY MESSAGES

- 1) Much drier air takes hold across the area today behind departing cold front.

- 2) A weak shortwave moving through the area on Tuesday may provide light showers or an isolated storm.

- 3) Showers and storms return for Wednesday and Wednesday night, as a cold front moves through the area. Some storms could be strong to severe. Precipitation then transitions to snow or a rain snow mix Thursday behind the departing front. In addition, gusty winds will take hold, with wind advisory headlines possibly needed across the higher terrain of the northern mountains.

DISCUSSION

KEY MESSAGE 1...

Cold front is slowly departing to the south of the area this morning. In its wake, much drier air is progged to move into the region. Once afternoon mixing commences, expect RH values to plummet into the 20 to 30 percent range, along with occasional gusty winds in the teens. Not expecting widespread fire issues due to recent rains, however, fuels will start to dry out across the area under these conditions.

KEY MESSAGE 2...

A weak shortwave will move through the area on Tuesday. This will provide an increase in cloud cover, and some light shower activity. An isolated storm cannot be completely ruled out during the afternoon, but overall coverage of any precipitation should be relatively limited.

KEY MESSAGE 3...

Showers and storms are expected to become more numerous Wednesday/Wednesday night with the approach of a trough and surface cold front. Front looks to generally move into the CWA Wednesday evening. Strengthening low level southwesterly flow out ahead of the front will advect above normal pw values into the area, with localized water issues not completely out of the question, mainly in locations that would get hit repetitively, as overall flow/speed of storms should be sufficient enough to prevent widespread issues. As far as severe threat, it's still relatively uncertain at this point. By the time the front comes in, it appears much of the instability will be waning. In addition, there still remains uncertainty in coverage of any activity earlier in the day and its effect on the environment. However, with the overall strong dynamics/shear expected with the system, there does exist a damaging wind threat during the period, and spc continues to highlight parts of the area for severe potential.

Behind the front, much cooler air will filter into the region for Thursday, with a transition to snow or a rain snow mix across areas. In addition, gusty winds will take hold for Thursday behind the front, with at least near advisory criteria winds expected across the higher terrain. At this point, expecting minimal impacts due to wintry weather with this system.

AVIATION /18Z MONDAY THROUGH SATURDAY/

VFR conditions will continue through today and tonight. CIGs lower late tonight into Tuesday morning, potentially bringing MVFR to northern terminals, although confidence remains low to medium in this occurring. Additionally, ISOLD showers/storms are possible Tuesday morning into the afternoon, potentially resulting in very brief MVFR VSBY if they were to move over a terminal.

Light southwest surface flow is expected throughout this TAF period (until 18Z Tuesday). Occasional breezes of 15-20 kts are possible this afternoon, with the same being the case beginning late Tuesday morning. Additionally, brief/marginal LLWS cannot entirely be ruled out tonight at a few sites, but given low confidence, has been left out of the TAFs for the time being.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE: High through tonight, medium thereafter. ALTERNATE SCENARIOS: LLWS could briefly occur tonight at a few sites. MVFR CIGs Tuesday morning into the afternoon may be more widespread than currently anticipated.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04 EDT 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H

AFTER 18Z TUESDAY... IFR conditions are possible in showers and thunderstorms Wednesday into Wednesday night, and in mixed wintry precipitation Thursday morning.

RLX WATCHES/WARNINGS/ADVISORIES

WV...None. OH...None. KY...None. VA...None.