FXUS66 KMFR 062149 AAA AFDMFR Area Forecast Discussion...UPDATED National Weather Service Medford OR 249 PM PDT Sat Jul 6 2024 .DISCUSSION...A multi-day heat wave is in progress as a strong ridge of high pressure remains in place over the region. This is bringing very hot and very dry conditions to inland areas. Dangerous, excessive heat remains the main concern into early next week. Excessive heat warnings (NPWMFR) remain in place In addition, breezy to gusty during the late afternoon and evening are expected today. These winds combined with heat and low humidities will result in elevated fire weather concerns across many areas of southwest Oregon and into western Siskiyou County. Breezy to gusty winds are forecast again on Sunday afternoon evening, especially in Douglas, Joesphine, Jackson, southern Klamath and western Siskiyou counties. Red Flag warnings are in effect for these conditions today and Sunday. Please see the RFWMFR and the fire weather discussion below for details. With this heat wave the hottest temperatures are likely to occur today through Monday, with afternoon high temperatures near or above 110 degrees in many valleys west of the Cascades and highs near 100 for valleys east of the Cascades. Overnight lows will remain above normal as well with only brief or very little relief from the heat. On Tuesday, a weak trough is forecast to move up from California and this result in slightly less hot temperatures. However, excessive heat is still expected into Tuesday, especially across inland valleys west of the Cascades. This is a multi-day heat wave with dangerous, excessive heat and little nighttime relief. Record or near record high temperatures are forecast including for Medford, Klamath Falls, Alturas and Mount Shasta City today and potentially again on Sunday and Monday. For areas along the coast, expect little in the way of low clouds except some patches of fog near Brookings and and north of Cape Blanco are possible in the overnight and morning hours. Temperatures will be above normal for coastal locations as well with highs in the upper 70s to upper 80s through Tuesday. As the shortwave trough moves up from the south beginning Tuesday, we are watching for any risk of thunderstorms. Moisture aloft still looks to be scarce with a very low chance (5%) for thunderstorms from the Cascades east and Siskiyous south. A broad tough moves into the region from the west mid to late week. This will allow temperatures to trend less hot. There also a continuing low chance (5%) for thunderstorms, mainly across northern California or from the Southern Oregon Cascades east. Confidence is low in the details during this period. && .AVIATION...06/18Z TAFS...VFR prevails across the CWA for the next 24 hours. Gusty north winds (~30kt) will impact North Bend through early this evening. Winds ease and light fog or mist could develop along the immediate coast late tonight or first thing Sunday. This may reduce conditions to MVFR or even briefly IFR; otherwise, VFR prevails there too. -Spilde && .MARINE...Updated 800 AM Saturday, July 6, 2024...Wind-driven steep seas persist in all waters today as northerly winds continue. This afternoon, northerly winds will pick up in most waters. The strongest winds will be angled to the southwest of the cape, with sustained speeds of 25 kt and gusts up to 35 kt. Lesser winds of 20 kt gusting to 30 kt will develop to the west and to the north of Cape Blanco. These winds won't be enough to change the sea state but are still worth acknowledging. Elevated winds south of Cape Blanco will continue into next week, supporting a continuing Small Craft Advisory limited to these southern waters through Monday evening. More widespread products may be needed in the middle and end of the week as a thermal trough strengthens, bringing gusty winds to all waters and possible periods of gale gusts to waters south of Cape Blanco. -TAD/CC && .FIRE WEATHER...Issued 200 PM Saturday July 6, 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 along and east of the Interstate 5 corridor 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. A red flag warning in in place today for portions of zones 616, 617, 620, 621, 622 and 623, 624, and 280 for today. Conditions on Sunday will be very similar to today, although winds are forecast to be much weaker east of the Cascades. Given the recent holiday, and despite no lightning in the forecast, there will continue to be other potential sources of ignition, and rapid spread of any new or existing fires will be a significant concern. A red flag warning has been issued for Sunday for zones 616, 617, 620, 621, 622, 623, and 624 in Oregon and zone 280 in California. Brief or near critical conditions may also occur in 281 and 282. Heading into Monday, a weak upper level wave is forecast slide through the region, and temperatures are expected to cool be a few degrees, while humidities improve my a few percentage points. This is expected to be just enough improvement to preclude additional Red Flag issuances, but conditions will be borderline, and just close enough to still warrant some concerns. The heat continues into next week. Additionally, by midweek, 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/BPN && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Excessive Heat Warning until 9 PM PDT Tuesday for ORZ023>026. Red Flag Warning until 8 PM PDT this evening for ORZ616-617- 620>625. Red Flag Warning from 2 PM to 8 PM PDT Sunday for ORZ616-617- 620>624. Heat Advisory until 9 PM PDT Tuesday for ORZ029>031. CA...Excessive Heat Warning until 9 PM PDT Tuesday for CAZ080>082. Red Flag Warning until 8 PM PDT this evening for CAZ280. Red Flag Warning from 2 PM to 8 PM PDT Sunday for CAZ280. Heat Advisory until 9 PM PDT Tuesday for CAZ083>085. PACIFIC COASTAL WATERS...Small Craft Advisory until 9 PM PDT Monday for PZZ356-376. && $$ CC