textproduct: Charleston

WHAT HAS CHANGED

Not much change with the forecast, strong to severe thunderstorms chances are increasing for the Saturday evening into Sunday timeframe. Aviation forecast update.

KEY MESSAGES

- 1) Daily chances for showers and thunderstorms through Saturday. Some storms may be strong to severe Friday and Saturday.

- 2) Multiple nights of frost and freeze possible starting Sunday night into next week due to cooler temperatures.

DISCUSSION

KEY MESSAGE 1...

Stationary front docked across our northern tier counties lifts north today as a warm front and will then remain parked there through Saturday. This will provide unseasonably warm, almost summerlike temperatures today through Saturday. This stout warm sector paired with shortwave disturbances moving through the upper-level will create daily chances for showers and thunderstorms each afternoon and evening.

Expecting mostly "garden variety" pulse thunderstorms today, especially across the mountains, but some may be strong to severe on Friday and Saturday with more support from upper-level disturbances. Damaging winds, hail, and heavy rainfall leading to localized flash flooding will be the main risks with storms on Friday.

Much of the same risks can be expected on Saturday, but Saturday's storms will be driven ahead of a strong cold front late Saturday afternoon and evening. Models are in a solid agreement, except the NAM which delays its arrival by 2 to 3 hours. Some models show scattered showers and thunderstorms forming across the southern mountains ahead of a main line of thunderstorms.

KEY MESSAGE 2...

Aforementioned strong cold front will knock our temperatures back quite a bit from what we have been experiencing starting Sunday. Temperatures are expected to be 5 to 10 degrees below normal starting Sunday through Wednesday (lowlands will be in the mid 50s to low 60s).

Overnight lows are projected to be in the 20s and 30s which will possibly lead to multiple nights of frost/freeze headlines across our active growing season counties(all of the lowlands and the southern mountains of VA and WV). This would be of concern from Sunday night through possibly Wednesday night, before a warming trend starts Thursday.

A clipper system will cross or graze our area sometime between late Monday and Tuesday. This system looks to be mostly dry, but there may be just enough fetch from the NW to bring some very light upslope snowfall across the higher elevations of the northeastern WV mountains Tuesday.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

VFR for most is expected today. FEW to SCT CU between 3,500 and 6,000 feet this afternoon. There area chances for some afternoon/evening showers and thunderstorms with higher likelihood(50-60%) across the northeastern mountains of WV(KEKN). Because of the lower chances elsewhere, have allowed VCTS and a few TEMPOs in the TAFs, namely for BKW, CKB, and CRW. IFR conditions are possible in and near any organized convective activity.

Showers or storms are expected to dissipate after sundown and CIGs will raise. VFR will prevail for most of night at most sites, but soundings show low stratocu decks will form across the northeastern mountains of WV tonight into Friday morning, mostly due to expected rainfall this afternoon. MVFR or lower could be possible with any low clouds. VFR will resume again under CU decks by ~14z Friday.

Winds will be out of the SSW and will be breezy at times with gusts between 15 and 20 knots. LLWS has been added for multiple sites starting at ~00z as winds will decrease after sundown and a nearby front will keep winds aloft sustained between 30 and 40 knots.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY... FORECAST CONFIDENCE: HIGH

ALTERNATE SCENARIOS: Timing, location, and intensity of showers and thunderstorms this afternoon and evening may vary.

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 FRIDAY... IFR conditions possible in and around showers and thunderstorms Friday afternoon and evening, then again Saturday afternoon into Saturday night.

RLX WATCHES/WARNINGS/ADVISORIES

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