textproduct: Fairbanks

SYNOPSIS

Warmer weather has arrived in the Interior and we are noticing our thunderstorm coverage increasing, especially in the Western Interior and along the Alaska Range today and tomorrow. Coverage increases in the Central/Eastern Interior tomorrow and Saturday with very warm temperatures, in the 80s expected. Thunderstorms and warm temperatures will also be prevalent in the Brooks Range and North Slope through Saturday but a cold front moves through Saturday into Sunday ending the warming trend on the North Slope. On the West coast, temperatures will remain cool with areas of showers south of the Seward Peninsula, but temperatures gradually warm this weekend with drying conditions.

KEY WEATHER MESSAGES

Central and Eastern Interior... - Very warm, widespread high temps increasing into the upper 70s today, then low to mid 80s tomorrow through Sunday.

- Showers and storms expected each day through the weekend and into next week. Scattered thunderstorms are expected, mainly across the southern Interior from Friday through Sunday, with isolated storms north.

West Coast and Western Interior... - Temperatures remain seasonably cool along the Coast with highs in the 50s to low 60s, warming this weekend with most spots in the low 60s from the Seward Peninsula south.

- Highs in the Interior in the upper 60s/low 70s today will rise into the mid to upper 70s by the weekend.

- Isolated thunderstorms for most of the Western Interior today, increasing in coverage on Friday from Ruby south/east. Thunderstorms may persist through the night, then continue on Saturday/Sunday but return to being isolated.

- Light to moderate rain in SW AK today will gradually end by early Friday morning. Totals will be 0.10 to 0.25".

North Slope and Brooks Range.. - Warm, highs in the 50s/60s along the coast and 60s/70s in the Plains through Friday. Gradually cooling on Saturday from west to east during the afternoon/evening with a cold front.

- Expect northern Brooks Range valleys to warm into the 70s and near 80 through Saturday, then drop on Sunday.

- Isolated thunderstorms each day through Saturday in the Plains and Brooks Range. More predominant in the southern Brooks Range on Sunday and into next week.

FORECAST ANALYSIS AND DISCUSSION

Our pattern continues to progress as expected with ridging building in from the southwest and northeast. We will remain a bit cloudy with chances for rain showers over the West Coast as a low keeps it unsettled today into tomorrow, but there will be improving conditions this weekend as the low drops south and ridging builds in. Otherwise, today through Saturday, expect increasing chances for thunderstorms from the North Slope to the AK Range and everywhere in between. Temperatures will be warm, well into the 70s and 80s for most of the Interior through the weekend with slightly cooler temperatures on the North Slope. Speaking of the North Slope, there will be a cold front swinging through from Saturday into Sunday. This front will spark some showers and thunderstorms as it does so, but the main chance will be temperatures cooling to near freezing along the coast with 50s to low 60s in the Plains and northern Brooks Range valleys.

Getting a bit more specific with the thunderstorms, there is still some uncertainty with the exactly placement of the most robust storms. As of now, today and tomorrow look to be the Alaska Range and Western Interior show, whereas Saturday and Sunday shifts into the Central/Eastern Interior. One of the big players with the weekend thunderstorms is a shortwave trough moving from the Gulf of Alaska into the Interior on Saturday. It is an amped piece of energy as it glides northward on Friday, but it should weaken as it approaches the AK Range and Interior on Saturday. Timing of this is crucial because it can directly impact numerous events going on in Fairbanks. If this wave moves in quickly on Saturday, thunderstorms may occur in the morning, leaving a quieter afternoon/evening. If this wave is a bit slower, it will make for a potentially eventful afternoon/evening in the Interior. Right now we are leaning towards an evening time frame, which would line up with peak heating and instability. One other piece of information is that this shortwave has trended slightly east, so the most robust thunderstorms should be in the Eastern Interior, but scattered thunderstorms are still expected across much of the area.

Nonetheless, the pattern continues as expected with warming temperatures in most spots and areas of showers and thunderstorms each day through the weekend and into next week. As with most thunderstorm events, erratic wind gusts, small hail, frequent lightning and heavy rain are all possible impacts. During this big weekend for Alaska, remember to stay weather aware and keep your eyes to the sky for thunderstorms.

FIRE WEATHER

As upper level ridging builds across the state, slow moving thunderstorms continue to be a threat, with growing confidence in higher thunderstorm activity from Healy through the Tanana Valley into the Alcan border. A Fire Weather Watch has been issued based of the convective nature of the weekend, stay tuned as we monitor guidance with the shortwave trough moving over the area Saturday; areas of concern might shift farther east. Keep a sharp lookout and be ready for strong gusts and lightning near and around dark rain producing clouds. As the AICC mentioned in their morning brief, this could be the largest lightning producing weekend of this fire season so far.

Accompanying thunderstorms will be some of the warmest temperatures of the summer so far. Across the Central/Eastern Interior, high temperatures in the upper 70s and low 80s expected Friday through Sunday. Along the Western Interior, highs will remain slightly cooler, likely in the low to mid 70s through Friday, then potentially seeing a few spots reach the upper 70s by the weekend. While relative humidity is generally expected to remain near 30 percent, there will be a few pockets of 20 to 25 percent in the Tanana Valley and Yukon Flats by tomorrow.

HYDROLOGY

After a wet week on the North Slope and Brooks Range, water levels in the rivers are receding. We have cancelled or expired all flood hazards and flooding is no longer expected. Rivers will return to near normal levels through the week and into the weekend.

EXTENDED FORECAST DAYS 4-7

Current model consensus favors weak ridging in the Interior through this time next week. As the ridge axis moves east and troughing digs just south of the Brooks Range, daytime temperatures in the Interior will drop down closer to climatological normals starting early next week. With another upper-level low gradually moving eastward in the Gulf of Alaska continuing to supply moisture and instability to the Interior, thunderstorm activity is expected to continue, especially in the Southern and Central Interior. On the other hand, guidance favors weak troughing for the North Slope for most of next week. There is a potential exception for Tuesday and Wednesday, when the GFS and Canadian models predict ridging will extend into the Eastern Arctic Coast, giving them a respite from generally cooler and showery conditions and bringing above average temperatures. Looking ahead to this time next week, some deterministic models indicate troughing may finally be able to move into the Interior bringing the return of cooler and unsettled weather, but ensemble guidance favors weak ridging through next weekend.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...None.