textproduct: NWS Flagstaff

SYNOPSIS

Drier and slightly breezy conditions through Thursday, with only isolated showers and thunderstorms each afternoon and evening. Precipitation chances increase again beginning Friday and into the weekend.

DISCUSSION

A trough over the west coast will continue to produce southwesterly flow over our region over the next few days. Drier air in the mid levels has also moved into northern Arizona, though sufficient low level moisture remains (dewpoints 45-55F) for a few showers and thunderstorms, primarily over the higher terrain of Coconino County. Isolated strong storms will be possible with the increased wind shear, mainly in northwest Arizona. Some very localized areas of heavy rainfall will be possible through early this evening as well. Breezy southwest winds will also develop each day, in the 15-20 mph range with gusts 25-30 mph. Daytime highs will be a few degrees cooler than normal. Starting as early as Thursday evening, models are indicating an increase in moisture from the south and higher chances for showers and thunderstorms. This should be in part due to a moisture surge up the Gulf of California as a tropical system moves well offshore the tip of Baja into the weekend (official NHC forecast track for TS Marie). There is still some uncertainty in where the deepest moisture tracks (AZ or farther west), but the increase will be enough to bring higher shower and thunderstorm coverage Friday through the holiday weekend. Our current forecasts indicate 30-60% chances each day, highest over higher terrain. This could also include some overnight storm activity. Daily high temperatures through the holiday weekend are currently forecast to be near to a few degrees below normal, but will be highly dependent on storm coverage.

AVIATION...Tuesday 01/18Z through Wednesday 02/18Z

VFR conditions expected. ISOLD-SCT SHRA/TSRA returns from 19-03Z, mainly along the higher terrain. Gusty/erratic winds possible near storms. Winds are light and VRB or terrain driven through 19Z, becoming SW 10-15 kts gusting to 25 kts. Winds return to light and VRB or terrain driven after 03Z.

OUTLOOK...Wednesday 02/18Z through Friday 04/18Z...VFR conditions expected. Winds are SW 10-20 kts each afternoon, light and VRB or terrain driven each night. ISOLD-SCT SHRA/TSRA each afternoon, with main impacts being gusty/erratic winds.

FIRE WEATHER...This afternoon through Thursday

Drier and breezy conditions continue. Isolated shower and thunderstorm chances continue each afternoon/evening, mainly over the higher terrain. Winds are southwest 10-20 mph with gusts up to 30 mph, strongest in northwest AZ. Daytime highs slightly below normal. Minimum RH is 30- 50% each day.

Friday through Sunday...Increasing moisture will cause shower and thunderstorm coverage to increase Friday through Sunday. Best chances will be seen near the White Mountains each day, with elevated potentials along other areas of higher terrain. Winds during the day will be southwest 10-20 mph with gusts to 30 mph on Friday, then south through southwest 5-15 mph Saturday and Sunday. Light and variable or terrain driven winds overnight. Minimum RH will be 35 to 65% each day.

FGZ WATCHES/WARNINGS/ADVISORIES

None.