6-Day Forecast

Today

Partly sunny, windy, mild, isolated afternoon showers and thunderstorms, highs near 70 degrees

Tonight

Mostly cloudy, windy, cool, chance for a shower or thunderstorm, lows in the lower 50’s

Friday

Mostly sunny, warmer, near 80 degrees

Friday Night

Partly cloudy, cool, low 50’s

Saturday

Mostly sunny, warm, near 80

Sunday

Mostly sunny, warm, near 80

Monday

Mostly sunny, warm, near 80

Tuesday

Partly sunny, warm, near 80

Discussion

An upper level ridge will take control of our weather as we approach the end of the work week and this will set us up for a nice holiday weekend. In fact, the weather forecast for Friday through Memorial Day can be basically summed up with “mostly sunny and warm with highs near 80 degrees” each day in that period of time.

6-Day Forecast

Today

Partly sunny, milder, isolated afternoon showers and thunderstorms, highs in the mid 70’s

Tonight

Mostly cloudy, cool, chance for a shower or thunderstorm, lows in the upper 40’s

Thursday

Partly sunny, pleasant, chance for a shower or thunderstorm, low 70’s

Thursday Night

Partly cloudy, breezy, cool, low 50’s

Friday

Mostly sunny, warmer, near 80

Saturday

Mostly sunny, warm, near 80

Sunday

Mostly sunny, warm, near 80

Monday

Partly sunny, warm, low 80’s

Discussion

Enough moisture will be around the region today for isolated showers and thunderstorms to form and that unsettled weather will continue into Thursday as well. By the end of the week, however, high pressure will take over and the weather will turn warmer and drier and that dry, warm weather will continue this weekend with high temperatures climbing to near 80 degrees each day.

One final note: the tornado that struck Oklahoma on Monday has now been upgraded to an "EF-5" classification level which is the most intense type on the "Enhanced Fugita" scale and it is suggestive of 200+ mph winds.

Video

http://www.youtube.com/watch?v=phbiaaLwpZk

Discussion

Tornadoes require clashes of air masses to form generally to include cold, dry air in the upper atmosphere and very warm and humid air in the lower atmosphere. For much of the spring, the missing ingredient for this scenario in the US was the influx of very warm and humid air from the Gulf of Mexico thanks in large part to the persistent cold pattern in the central and eastern US that acted to inhibit Gulf of Mexico air from advancing northward. The cold air masses, however, began to retreat a couple of weeks ago and subsequently, dew points, which are a true measure of moisture content in the air, have consistently climbed in the central and eastern US and this increased dramatically the prospects for severe weather.

Indeed, the combination of very warm and humid low-level air with a vigorous cold upper-level low pressure trough on Monday helped to spawn the powerful tornado that struck portions of Oklahoma with a major impact on Moore, a heavily populated (50,000 residents) suburb of Oklahoma City some twenty miles to its south. The preliminary estimate is that the one-to-two mile wide tornado that struck the town of Moore reached EF-4 status on the “Enhanced Fugita” scale (5 being the most intense) with winds of nearly 200 mph, but these estimates will be re-evaluated over the next several days/weeks as tornado experts on the ground closely assess the damage and I think it may very well end up being classified as an EF-5. The tornado lasted for about 40 minutes causing destruction over a 20 mile swath.

The overall weather pattern that helped to produce the severe weather yesterday (i.e., warm, humid low level air, strong cold upper-level low with a powerful jet streak, strong surface cold front) will continue for the next couple of days with the severe weather threat zone slowly shifting eastward. There is a threat today for severe weather from the southern Plains to the Upper Midwest, and then likely in the Ohio Valley on Wednesday, and then perhaps in the Mid-Atlantic and Northeast US late Thursday as a strong cold front approaches the east coast. Strong-to-severe thunderstorms are possible later Thursday in the region from the Carolinas to New England as all the atmospheric dynamics shifts towards the east coast. This afternoon’s video includes some time-lapse video of yesterday’s tornado and a detailed discussion as to why the previously quiet tornado season has ended.

Video

http://www.youtube.com/watch?v=XWgG6npVG_0

6-Day Forecast

Today

Mostly cloudy early with scattered showers possible, some sun late, cool, highs in the mid 60’s

Tonight

Partly cloudy, chilly, lows in the low-to-mid 40’s

Wednesday

Partly sunny, milder, maybe a shower or thunderstorm, mid 70’s

Wednesday Night

Mostly cloudy, cool, a shower or thunderstorm possible, upper 40’s

Thursday

Mostly sunny, breezy, mild, chance for a shower or thunderstorm, low 70’s

Friday

Partly sunny, warm, near 80

Saturday

Mostly sunny, warm, low 80’s

Sunday

Partly sunny, warm, low 80’s

Discussion

Cooler weather began the new week and will continue today as high temperatures hold at below normal levels in the middle 60’s. An upper level ridge will move across the state on Wednesday and this will allow for some warmer conditions although a shower or thunderstorms cannot be ruled out in the mid-week time frame. Drier and warmer conditions are likely in the southern Rockies this weekend.

Video

http://www.youtube.com/watch?v=cU7GdZBRwBU

6-Day Forecast

Today

Mostly cloudy, cool, showers likely and possibly a thunderstorm, highs in the low 60’s

Tonight

Mostly cloudy, colder, chance for showers and thunderstorms, lows in the low-to-mid 40’s

Tuesday

Mostly sunny, a bit milder, upper 60’s

Tuesday Night

Partly cloudy, cool, mid 40’s

Wednesday

Partly sunny, warmer, maybe a shower or thunderstorm, low-to-mid 70’s

Thursday

Partly sunny, pleasant, breezy, mid 70’s

Friday

Partly sunny, warm, slight chance for a shower or thunderstorm, mid-to-upper 70’s

Saturday

Partly sunny, warm, low 80's

Discussion

Cooler weather will begin the new work week as high temperatures hold at below normal levels in the lower 60’s. The upper level trough causing today’s cooler conditions will move away to our east on Tuesday and this will allow for warmer conditions here by mid-week with high temperatures getting back to the 70’s.

Video

http://www.youtube.com/watch?v=1I_gT1PXSWM

Discussion

The active sunspot region called AR1748 unleashed an M-class solar flare at 0858 UT on Friday, May 17th. While this is not the strongest flare that we’ve seen from AR1748, it actually may be the most geoeffective as this sunspot is now facing the Earth more directly than before, and the explosion might have hurled a coronal mass ejection (CME) towards the Earth.

Another CME that was sent into space earlier this week by an X1-flare from the same sunspot region might deliver a glancing blow to the Earth’s magnetic field later tonight. NOAA forecasters estimate a 40% chance of polar geomagnetic storms when the cloud arrives. High-latitude sky watchers should be on alert for northern lights later tonight.

Stay tuned.

6-Day Forecast

Today

Mostly sunny, warm, highs in the mid-to-upper 80’s

Tonight

Partly cloudy, cool, lows near 50 degrees

Saturday

Partly sunny, not as warm, maybe a shower or thunderstorm, low-to-mid 70’s

Saturday Night

Mostly cloudy, cool, chance for a shower or thunderstorm, near 50

Sunday

Mostly cloudy, cooler, chance for a few showers and thunderstorms, mid-to-upper 60’s

Monday

Partly sunny, cool, chance for a shower or thunderstorm, low 60’s

Tuesday

Partly sunny, cool, upper 60’s

Wednesday

Partly sunny, milder, mid 70’s

Discussion

Warm weather will continue for another day, but then a broad upper level trough will move into the southern Rockies this weekend and bring somewhat cooler weather to the region along with possible scattered showers and thunderstorms. Moisture will likely be rather limited with this upper level trough of low pressure so significant rainfall is not likely. Cool weather early next week will give way to a warmer air mass by the mid-week time frame.

Video

http://www.youtube.com/watch?v=zGUFJ-4TiIE

Discussion

The active sunspot region called AR1748 has unleashed four X-class solar flares in the past few days and it might not be finished yet as it continues to grow and has a magnetic field that harbors energy for more X-class solar flares according to NASA scientists. (Other solar flare categories include M-class, which are medium strength and C-class which are small and relatively weak). This particular sunspot region has actually produced more X-flares than every other sunspot of the past year combined.

The last of the four solar flares which occurred early yesterday did produce a coronal mass ejection (CME) that may deliver a glancing blow to Earth’s magnetic field on Friday, May 17th. As a result, northern lights are possible across northern latitudes when the CME reaches the Earth’s upper atmosphere on Friday. The threat for more X-flares continues from AR1748 as it now moves into a location that puts the Earth directly in the line of fire. NOAA forecasters put the odds of another X-flare at 60%. The largest X-class solar flare in this particular solar cycle (#24) was an X6.9 that occurred on August 9th, 2011.

Stay tuned.

Video

http://www.youtube.com/watch?v=l8HO2ELAhrw

6-Day Forecast

Today

Mostly sunny, warm, chance for a shower or thunderstorm, highs in the low 80's

Tonight

Partly cloudy, cool, lows near 50 degrees

Friday

Mostly sunny, warm, low 80’s

Friday Night

Partly cloudy, cool, low 50’s

Saturday

Partly sunny, mild, low-to-mid 70’s

Sunday

Partly sunny, cooler, chance for a shower or thunderstorm, mid 60’s

Monday

Partly sunny, cooler, chance for a shower or thunderstorm, low-to-mid 60’s

Tuesday

Partly sunny, cool, upper 60’s

Discussion

Generally warm weather will continue for the next couple of days with only a slight chance for a shower or thunderstorm. A broad upper level trough will move into the southern Rockies later this weekend and bring somewhat cooler weather along with possible scattered showers and thunderstorms. Moisture will likely be limited with this upper level trough of low pressure so significant precipitation is not likely.

Video

http://www.youtube.com/watch?v=WxFj57FYNnA

6-Day Forecast

Today

Partly sunny, not quite as warm as yesterday, chance for afternoon showers and thunderstorms, highs in the upper 70’s

Tonight

Mostly cloudy, cool, chance for a shower or thunderstorm, lows near 50 degrees

Thursday

Mostly sunny, warm, upper 70’s

Thursday Night

Mostly cloudy, cool, low 50’s

Friday

Partly sunny, warm, low 80’s

Saturday

Partly sunny, mild, chance for a shower or thunderstorm, mid 70’s

Sunday

Partly sunny, cooler, chance for a shower or thunderstorm, upper 60's

Monday

Partly sunny, cool, mid 60’s

Discussion

Generally mild weather will continue for the next few days with isolated showers and thunderstorms in the region. A broad upper level trough will move into the southern Rockies this weekend and bring somewhat cooler weather to the region along with possible scattered showers and thunderstorms.

An update on the sun - there has been a fourth "X-class" solar flare from the very active sunspot region called AR1748 that occurred earlier today. Before the week began, the sun had not unleashed any X-class flares, but now there have been four in just the past few days.

Video

http://www.youtube.com/watch?v=zKQUZuEUxsE