Winnemucca, NV 89445 Weather

Key Messages

* Periods of valley rain and mountain snow Tuesday thru Friday.

* Isolated thunderstorms expected each afternoon Tuesday thru Thursday.

* Cooler the latter half of the week and this weekend.

Discussion

(Today through next Tuesday)

WEATHER PATTERN OVERVIEW: Deep upper level low pressure continues to circulate off the California coast this morning and moisture from the south will continue to push north. Favorable dynamics will produce isolated to scattered showers with the likelihood of a few rumbles of thunder by this afternoon, primarily within central Nevada and portions of eastern Nevada as activity moves in from the south as indicated. Forecast surface- based CAPE values will be in the 100 to perhaps 150J/kg range with weak instability denoted by slightly negative lifted indicies. Daytime high temperatures will be in the low 60s to low 70s with overnight lows primarily in the 30s.

Wednesday thru Friday, the upper closed low will slowly and gradually move inland on Wednesday. From here, latest numerical model solutions indicate that the low will weaken into an open wave and cross into southern and central Nevada Thursday and Friday with the trof axis situated directly over Nevada Thursday night. Model trends have been consistent in showing this to be a warm storm with snow levels above 8000 feet. Rainfall amounts in the valleys Wednesday thru Friday remain relatively robust at around a half- inch with some valley accumulations nearing an inch within portions of central Nevada. Daytime high temperatures during this period will be warm on Wednesday with readings still in the low 60s to low 70s, but cooling around ten degrees by Thursday with low 50s to low 60s forecast. Temperatures will be a few more degrees cooler Friday. Winds will be breezy to locally windy each afternoon, especially in central Nevada where gusts to 30-40 mph are expected. Overnight lows cool to the mid 20s to mid 30s for Thursday night, becoming mid teens to mid 20s by Friday night.

The upper system is expected to shift east and out of the forecast area Saturday with dry conditions expected into early next week. Temperatures warm a few degrees thru the weekend, residing near seasonal normals early next week.

FORECAST CONFIDENCE & DEVIATIONS: Significant changes to PoP and weather fields thru the short term. Confidence in the short term forecast remains high, though there are slight differences in the timing and location of convective activity Tuesday and Wednesday.

Aviation

-SHRA and/or VCSH will be forecast at all terminals beginning today as active weather moves in from the south. That said, CIGS are expected to remain within VFR category. Lower confidence in TS impacting any terminals this afternoon with the best potential being at KTPH, KELY, and KENV. Will likely include a PROB30 group for TS at the mentioned terminals in the TAF as TS will most likely be present within the broader area. Winds will become breezy to locally windy as well, primarily across the central Nevada terminals with gusts around 25KT.

Fire Weather

An upper level system will slowly move into the Great Basin from the west, bringing rain showers and mountain snow to all FWZs. Light showers begin to move into central Nevada from the south this afternoon with isolated thunderstorms also forecast, primarily within FWZs 426, 427, 425, 469, and 470. Shower and afternoon thunderstorm activity is expected to increase Wednesday and Thursday before dissipating from west to east Friday, eventually exiting Nevada Friday night. Widespread wetting rains are expected over the four day period and valley rainfall accumulations will be greatest within central Nevada with valley locations forecast to receive between one- half inch and one inch. Rainfall accumulations will be greatest on Thursday as the upper level system passes overhead. Breezy to locally windy conditions can also be expected each afternoon thru Friday, especially in central Nevada where gusts as high as 30-40 mph are expected. Cooler temperatures will be in place beginning Thursday and thru the weekend. Weather will be dry and generally fair this weekend.