Marine Weather and Tide Forecast for Union, WV

NEAR TERM /THROUGH FRIDAY NIGHT/
AS OF 230 PM EDT Thursday...

Key Messages:

1) Windy conditions continue

2) Chance of upslope precipitation overnight and into Friday

The cold front will be fully through by Friday, however the wind gusts will still persist for the next few days. Aided by a low level jet that remains over the Mid-Alantic, wind gusts will remain strongest at higher elevations though they will be a little weaker than Thursday. Sustained winds of 10-20 mph are expected to continue into Thursday night and Friday with wind gusts of 25-35 mph forecast in mountainous areas along and west of the Blue Ridge.

Drier and cooler air will become more noticeable as dew points will drop to the lower 30s and 40s and Friday morning temperatures will be in the 40s and 50s. Wind chills will likely go as low as the 30s at higher elevations. An upper level cut-off low will dip slightly southward to send a few shortwaves to the region but with such dry air (PWATs as low as 0.25 inches) any precipitation will likely be upslope and confined to the western mountain counties. Western Greenbrier currently looks to be the place to receive the most precipitation if any develops.

Confidence in the wind forecast is high.
Confidence in the temperature forecast is high.
Confidence in the precipitation forecast is average.

SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/
As of 230 PM EDT Thursday...

Key Points: 1. Dry Friday and Saturday.
2. Showers return Sunday.
3. Below normal temperatures.

A look at the 22 May 00Z NCEP Ensemble Mean 500mb Geopotential Heights shows a closed upper low Friday evening centered over New England. An upper ridge was situated from the Rockies north to Hudson Bay. By Saturday evening, little movement is expected for the upper low the center over the Canadian Maritimes. Additionally, little change is also expected for the ridge. By Sunday evening, there is still little change in the ridge/trough pattern noted above. Flow across our region is expected to be zonal.

At the surface, Friday evening low pressure will be situated near ME with an associated trough axis extending southwest just onshore into the Carolinas. High pressure will extend south from Hudson's Bay to the Gulf Coast states. Low pressure will be over the Four Corners region. For Saturday and Saturday night, little change is expected in the surface features from Friday. For Sunday/Sunday night, the ridge axis shifts east and covers much of the mid-Atlantic region. The Four-Corners low shifts east into TX. An associated warm front develops east of this low and extends into the Gulf Coast States.

A look at the 22 May 00Z NAEFS Ensemble Situational Awareness data shows 850mb temperatures ranging from +3C to +7C, n-s, across the area. These values correspond to the 2.5 to 10 percentile of the 30- year CFSR climatology. For Saturday, values increase to roughly +7C to +10C, n-s. On Saturday night, values are slightly milder than those of Friday night with +5C to +10C, ne- sw. Value continue an upward trend, reaching +8C to +12C, ne-sw on Sunday and on Sunday night.

The above weather patterns offer the following forecast. Little in the way of precipitation Friday night through Saturday night.
Showers return to the forecast Sunday into Sunday night with the proximity of the warm front to our south. While temperatures are expected to creep upward through the period, values will be below normal for this time of year.

Confidence in the above weather scenario is high.

LONG TERM /MONDAY THROUGH THURSDAY/
As of 230 PM EDT Thursday...

A look a the 22 May 00Z NCEP Ensemble Mean 500mb Geopotential Heights shows on Monday an upper ridge extending from the Four Corners region north then northeast towards Hudson Bay. A trough is expected to be centered over Newfoundland and Greenland. A weaker trough will be situated west to east over the Upper Mississippi Valley into the western Great Lakes region. Flow across our region is zonal. By Tuesday into Tuesday evening, the trough swings east into the eastern Great Lakes region and Lower Ohio Valley. Flow over our area starts to back southwest. On Wednesday into Wednesday evening, the axis of the trough shifts into our area. Ridging continues over western CONUS. By Thursday, the trough is expected to have amplified a bit, and be centered over or just east of our region.

At the surface, on Monday/Monday night will be situated from the Great Lakes region to New England. Low pressure will be over TX with an associated warm front extending east into the Gulf Coast States.
For Tuesday/Tuesday night, high pressure will be centered over the western Great Lakes with a ridge axis extending south into the Central Plains states. For Tuesday/Tuesday night, little movement is expected regarding the surface high. Low pressure is expected to move east along the warm front then progress into Lower Ohio Valley. For Wednesday/Wednesday night, the central US ridge expands in area and shifts southeast. This shift towards the southeast continues on Thursday with the high expected to be over the Lower Ohio River Valley by evening.

A look at the 22 May 12Z NAEFS Ensemble Situational Awareness data shows 850mb temperatures on Monday ranging from +10C to +13C, ne-sw.
Similar values are expected Monday night. On Tuesday, values will range from +10C to +13C, nw-se. Tuesday night, expect a small drop to +9C to +11C, nw-se. On Wednesday, anticipate values of +10C to +12C, nw-se. For Wednesday night, expect +7C to +10C. For Thursday, expect a fairly uniform +11C to +12C over the region.

The above weather patterns offer the following forecast. We will remain in a wet pattern on Memorial Day with the warm front still immediately to our south. On Tuesday, low pressure will approach the region, first lifting the warm front north across our region, and then passing to our north with its associated cold front then crossing the area Tuesday evening. On Wednesday, the first low and its associated weather exits the region, but a secondary low moving through the eastern Great Lakes will help keep clouds and the chance of precipitation over parts of the region. On Thursday, high pressure will start to be building into the area. However, its center still may be too far west to preclude residual upslope flow showers across the mountains. Temperatures should trend milder through the period, reaching values near normal by Wednesday/Thursday.

Confidence in the above weather scenario is moderate.

AVIATION /19Z THURSDAY THROUGH TUESDAY/
As of 230 PM EDT Thursday...

A cold front continues to move through the region today and is bringing gusty winds behind it. A gust of 36 kts was already reported at KBLF earlier this morning. Clouds have been clearing mostly and all terminals are at VFR status. A shortwave overnight may bring some more cloud cover with ceilings reaching MVFR for KBLF, KLWB, and KBCB. These clouds will lift by tomorrow (Friday)
afternoon but the strong winds will persist with gusts of 20-25 kts possible for all terminals.

Confidence in this forecast is average.

EXTENDED AVIATION OUTLOOK...

The vicinity of a surface high pressure system will keep all terminals VFR though windy conditions are expected to continue into the weekend. Early next week offers multiple chances of widespread precipitation and sub-VFR conditions for all terminals.

RNK WATCHES/WARNINGS/ADVISORIES
VA...None.
NC...None.
WV...None.