Area Forecast Discussion
Issued by NWS Medford, OR
Issued by NWS Medford, OR
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689 FXUS66 KMFR 060354 AFDMFR Area Forecast Discussion National Weather Service Medford OR 854 PM PDT Fri Jul 5 2024 .UPDATE...Evening update here to expire Red Flag for the west side and also to refresh the NPW for heat. 4 daily high temperature records were broken in our area this afternoon today. North Bend set a record high of 85 degrees. The previous record was 74 set in 1913. Medford set a record of 109 degrees today. The previous record was 102 set in 1926. Roseburg set a record high of 104. The previous record there was 98 set in 2023. Lastly, Montague set a record of 108 degrees. The previous record there was 105 set in 2007. Thankfully we have not observed any significant fire activity in satellite data this afternoon or evening. Skies remain clear as the area starts to cool off from the roasted Friday. Low temperatures tonight in the valley areas west of the Cascades will be generally in the upper 60s, which isn`t too relieving considering the magnitude of heat experienced today. East side valleys will be more pleasant with overnight lows in the 50s and some cool pockets of 40s north of Chiloquin. Bracing for a very hot Saturday with more records on the way. Additional forecast details in previous discussion below. Stavish && .AVIATION...06/00Z TAFS...A very dry air mass will lead to VFR conditions for all areas through the TAF period. /BR-y && .MARINE...Updated 800 PM Friday, July 5, 2024...Northerly winds under a persisting thermal trough continue to bring wind-driven steep seas to all waters. While seas are just at Advisory thresholds, the wide area and duration of the continuing hazard supports a Small Craft Advisory for nearly all areas through Saturday evening. The pattern will then change as the thermal trough restrengthens, and winds and seas increase again, especially south of Cape Blanco, with at least Small Craft Advisory conditions then expected to persist well into early next week. -BPN && FIRE WEATHER...Issued 230 PM Friday July 5, 2024...Heatwave underway and main concern for this period remains heat, winds, low humidities and unstable conditions contributing to fire danger through the weekend. The combination of wind and low humidity is expected to reach critical conditions for inland areas from the Cascades west in Oregon today. Forecast humidities range from the upper single digits to low teens and winds range from sustained 6-12 mph with gusts to around 20 mph. The main areas of concern for this afternoon and evening is the low elevation I-5 corridor from Roseburg to Grants Pass, Medford, and Ashland. A red flag warning in in place for portions of zones 616, 620, 621, 622 and 623 for today. Worsening conditions are expected on Saturday with slightly hotter, slightly drier, and slightly stronger winds expected across a broader area, including east of the Cascades into zones 624 and 625. The HDW (Hot Dry Windy) indices showing the condition as advertised by the GEFS members to fall within the top 5% of these events over the 30-year climatology from 1981-2010. In short, this is very unusual to have the area this hot, dry and (breezy) for this time of year. So, this occurring across the holiday weekend was the final consideration. Despite no lightning, there will be other potential sources of ignition. A red flag warning is in place on Saturday for zones 616, 617, 620, 621, 622, 623, 624 and 625 in Oregon and zone 280 in California. Brief or near critical conditions may also occur in 281 and 282. Hot, dry and gusty conditions continue into Sunday. Winds may trend slightly lower though compared to Saturday but critical or near critical conditions are likely. So a fire weather watch remains in place for these conditions. The heat continues Monday and Tuesday. Additionally, a short wave trough is advertised to come up the northern California coast which is a pattern often supportive of thunderstorms. But, not seeing the moisture to get us worried at this point and model guidance is showing a only a very low chance (10% or less) for thunderstorms Tuesday afternoon/evening and into Wednesday, mainly for the Cascades east and Siskiyous south. Watch for updates on this development. -CC && .PREV DISCUSSION... /Issued 441 PM PDT Fri Jul 5 2024/ It`s another hot afternoon with temperatures already in the 95-105 degree range in many west side valleys. Temperatures will warm to the 105-115 degree range, nearly 15-25 degrees above normal for this time of year. Medford, Klamath Falls and Mount Shasta will be in record breaking territory today, and this trend will continue through early next week. The warmest day of this stretch is coming tomorrow while the ridge moves inland over western Oregon. Tomorrow will begin with morning temperatures in the 50s east and in the 60s west. Tomorrow afternoon is when Medford has a ~40% probability to tie the all time recorded high temperature of 115 and Roseburg has ~45% chance for reaching 110. The Excessive Heat Warning west of the Cascades and Heat Advisory east of the Cascades will be in effect through this time. Winds tomorrow afternoon will also be stronger east into Klamath and Lake counties where gusts near 30 mph are possible. This, combined with low RHs, will bring a fire weather concern and Red Flag Warning tomorrow afternoon. Sunday will bring a cooldown of a few degrees, meaning there will be temperatures comparable to this afternoon with highs nearing 105-110 at their peak. With the newest data in, have extended the Excessive Heat Warning for Western Siskiyou, Jackson, Josephine counties through Tuesday. There was an area of concern of an advisory into more of the Umpqua Basin, but with probabilities nearing 50% on the forecast temperatures in this area wanted to hold off on this. Overall, highs in the 90s are forecast in the long term with triple digits possible in the Rogue Valley. -Hermansen && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Excessive Heat Warning until 9 PM PDT Tuesday for ORZ023>026. Red Flag Warning from 3 PM to 8 PM PDT Saturday for ORZ616-617- 620>625. Fire Weather Watch from Sunday afternoon through Sunday evening for ORZ616-617-620>624. Heat Advisory until 9 PM PDT Monday for ORZ029>031. CA...Excessive Heat Warning until 9 PM PDT Tuesday for CAZ080>082. Red Flag Warning from 3 PM to 8 PM PDT Saturday for CAZ280. Fire Weather Watch from Sunday afternoon through Sunday evening for CAZ280. Heat Advisory until 9 PM PDT Monday for CAZ083>085. PACIFIC COASTAL WATERS...Small Craft Advisory until 9 PM PDT Monday for PZZ350-356-370-376. && $$