Monsoon Classroom: The Great Basin High
Courtesy: NWS Tucson
As we enter the first full week of Monsoon 2013, I'll be explaining the patterns that bring the storms on Tucson Today and the blog. Today's Monsoon Classroom breaks down the Great Basin high.
This pattern almost always lends itself to severe weather. High pressure normally over the Four Corners gets shoved westward, parking over southern Nevada. Ample moisture and an unstable atmosphere fires up storms over the Mogollon Rim, which race southwest toward the valley floors. What sets this pattern apart from the others is changing wind direction and speed with height, known as wind shear. The more wind shear present, the better the chance storms organize into a squall line producing damaging winds.
It should be noted that wind shear can also sustain storms much longer than the Four Corners high pattern discussed yesterday. Many times during the Great Basin high scenario, southern Arizona can get a line of storms lasting well past midnight.
Click here to read more about the Great Basin high pattern on the NWS Tucson page. I'll break down the trapping high Monsoon storm pattern tomorrow.
Tuesday’s Tucson Forecast: Meager Monsoon flavor this week
THE CLIFF NOTES
Today - Sunny, hot again. 105°, west wind 10-15 MPH. MONSOON PREDICTION INDEX: 0/10 - no storm threat
Tonight - Clear. 72°, winds southeast 5-10 MPH. MONSOON PREDICTION INDEX: 0/10 - no storm threat
Tomorrow - Sunny. 105°, west wind 10-15 MPH.
Click here for my True View 4 video forecast
THE SHORT TERM
The triple digit streak continues, building to 18 straight days later this afternoon. Metro high temps on this Tuesday top out around 102-105° as high pressure sits south of the border. Winds aloft remain out of the west-southwest, shoving Monsoon moisture well east of the state. Not helping matters is a slow moving storm system over the Pacific Northwest. That features likely keeps the dry air in place the remainder of the week.
Of note, the White Mountains of Graham and Greenlee County will be under a Red Flag Warning tomorrow afternoon. Read more about that on NWS Tucson's website here.
THE LONG TERM
The westerly winds start to shift early next week, becoming more southerly. I think enough moisture returns for a chance of isolated mountain storms by Sunday and Monday. Above shows the Monday afternoon precip forecast from the Euro model. Biggest threat with this activity should be dry lightning strikes, further increasing the wildfire threat. Valley floors should remain dry over the next 7 days while we wait for deeper moisture to be imported from the south.
THE WORST WEATHER IN THE COUNTRY TODAY IS...
We would kill for 90° temps. Alaska, on the other hand, is trying to find ways to keep cool from Summer's swelter. Low to mid 90's are in the forecast this afternoon across southwestern Alaska as high pressure parks over The Last Frontier. Keep in mind typical highs up there are in the 50's and 60's this time of year. Rare and extreme heat indeed.
PICTURE TIME!
We won't be seeing much of this the next few days: cumulus clouds cropping up over the Catalinas. Larry Wasielewski snapped this Saturday as we saw our first storms of Monsoon 2013. Heading into the weekend, mountain cloud build-ups might be as good as it gets. Still lots of inroads to be made for those dew points to rise. Thanks for the photo Larry!
Tucson’s Monsoon 2013 Forecast
Courtesy: Greg McCown
For the fourth straight year, I've done extensive research to forecast an exact rainfall total for the upcoming Monsoon. The following is my thoughts on a variety of factors, from El Nino/La Nina to what impacts a late 1st 100° day has on the Monsoon.
So what can we expect this Summer? Here's my official Monsoon 2013 forecast for Tucson.
WHAT DOES THE CLIMATE PREDICTION CENTER (CPC) SAY?
Between July and September, the CPC says Tucson has equal chances of above, normal and below average precipitation. What exactly does that mean? Based on several different models and initial weather conditions, the CPC could not find any odds that favor a wetter or drier than normal Monsoon.
One thing they did find odds on was above average temperatures for the Summer. Not surprising considering the first half of June was the hottest ever in Tucson's history. More on that in a bit.
WHAT DOES THE EASTERN PACIFIC OCEAN SAY?
For the second year in a row, we're starting off the Monsoon with near normal water temps in the Eastern Pacific. That doesn't look to change the next few months. All the lines above indicate different computer models for water temps, which keep them between -0.5° (La Nina) to 0.5° (El Nino). Long story short, the eastern Pacific water temps will have little impact either way on Monsoon 2013.
A RELATIONSHIP BETWEEN NO EL NINO/LA NINA AND A LATE 1ST 100° DAY?
After combing through 60+ years of El Nino history, I found a correlation between neutral ocean temps and Tucson hitting its first 100° day in June. Since 1950, there have been 7 years where a late 1st 100° occurred in June during El Nino/La Nina free conditions. Monsoon rainfall totals for those years were:
1952: 5.61" 1967: 6.43"
1959: 6.71" 1979: 4.69"
1961: 6.68" 1981: 8.23"
1962: 4.97"
That boils down to an average Monsoon rainfall total of 6.21", which is above Tucson's historical average of 6.08".
WHAT ABOUT OUR RECORD JUNE HEAT?
The start of June 2013 in Tucson is the hottest ever. Does this mean we could be in store for a wetter than normal Monsoon? I did the math on the top 10 hottest June's and found the average rainfall to be 6.66". Like the relationship between no El Nino/La Nina & a late 1st 100° day, that's above the historical average of 6.08". It should be noted, however, that none of these 10 years had El Nino/La Nina free conditions through the Monsoon.
MY CONCLUSION
Between June 15th and September 30th, I'm predicting a Monsoon 2013 rainfall total of 6.14" for Tucson. This prediction is slightly above the 118 year normal of 6.08”.
I'll admit that this Monsoon is one of the toughest to call. As many signs as there are to above average rainfall, there's counter-arguments with the biggest being a lack of an eastern Pacific influence. My early prediction for Monsoon 2013 was to be drier than normal. Based on the above, I'm following the CPC and calling for near-normal rainfall.
Monsoon Classroom: The Four Corners High
As we enter the first full week of Monsoon 2013, I'll be explaining the patterns that bring the storms on Tucson Today and the blog. Today's Monsoon Classroom dissects the most common storm set-up for southern Arizona: the Four Corners high.
This pattern is responsible for the seasonal wind shift (AKA the Monsoon), developing in late June/early July. High pressure anchors over the Four Corners, with winds aloft out of the east or southeast. These winds draw in maritime tropical air from the Gulf of Mexico/mainland Mexico to southern Arizona, boosting dew points at or above 54°. The result? Thunderstorms forming around late morning, moving west as the day progresses.
Among the biggest severe weather threats with the Four Corners pattern is flash flooding and microburst winds. If conditions are favorable, storms can organize into a line and create large-scale straight line winds over 60 MPH.
Click here to read more about the Four Corners high on the National Weather Service website. I'll break down the second Monsoon storm pattern tomorrow, known as the Great Basin high.
Monday’s Tucson Forecast: Monsoon storms fizzle, temps sizzle
THE CLIFF NOTES
Today - Sunny, hot. 106°, west wind 10 MPH. MONSOON PREDICTION INDEX: 1 - low
Tonight - Clear skies. 73°, southeast wind 5 MPH.
Tomorrow - Sunny, scorching. 106°, west wind 10-15 MPH. MONSOON PREDICTION INDEX: 1 - low
Click here for my True View 4 video forecast
THE SHORT TERM
Monsoon 2013, where art thou? Our atmosphere is drying out big time thanks to a southwesterly flow aloft. Monsoon moisture's been punted south and east, indicated by the light blue and green over Texas and Mexico. Dry air heats up rapidly and we'll be in the 104-107° range metro-wide this afternoon. Mark today the 17th triple digit day in a row, adding to the record hot start to the month.
THE LONG TERM
Dry and hot weather rules the work week. We may see winds aloft shift a little more southerly by the end of the week, carrying in some moisture but not enough to warrant a storm chance. Mountain build-ups look like the better bet as soon as Thursday, with isolated storms possibly returning early next week for the mountains. If we stay in the 100's through Sunday, our triple digit streak will reach 23 days according to my St. Cloud State math.
THE WORST WEATHER IN THE COUNTRY TODAY IS...
A good news/bad news scenario on Colorado's Front Range today. Showers and storms are in the forecast, which helps fire crews gain an upper hand on several wildfires. However, some storms may become severe with large hail and damaging winds. This is highlighted by the Storm Prediction Center, who has put out a slight risk for severe storms in that area.
PICTURE TIME!
Gotta love this photo sent to us by Andrew Vock, who spent his weekend up at Roper Lake outside Safford. Beautiful sunset and sightlines captured Saturday evening. Andrew reports only a sprinkle while camping this weekend. More than what I got in Oro Valley! Thanks for the pic Andrew.
Friday’s Tucson Forecast: Monsoon making some noise next 48 hours
THE CLIFF NOTES
Today - Mostly sunny, isolated storms south & east of Pima County. 102°, west wind 10-15 MPH.
Tonight - Mostly clear. 77°, southeast wind 5 MPH.
Tomorrow - Mostly sunny, isolated storms south & east of Pima County. 102°, west wind 10-15 MPH.
Click here for my True View 4 video forecast
THE SHORT TERM
Second day in a row where dew points have been up across southern Arizona. Enough moisture's in play for a chance of isolated storms across the mountains, Santa Cruz and Cochise Counties this afternoon. Primary threats include gusty winds and dry lightning with little in the way of measurable rainfall. North of a Nogales-Benson-Willcox line, expect dry and hot conditions. A similar forecast scenario takes shape tomorrow for the first official day of Monsoon 2013.
THE LONG TERM
Winds aloft today are out of the southeast, drawing in some Monsoon moisture. Those winds shift to the southwest by Father's Day, drying out the atmosphere and heating us up. High temps Sunday through late next week peak in the 103-105° range under sunny skies. Not seeing any signs of a cool-down, increasing the odds that June 2013 becomes the first June ever with each day reaching triple digits.
THE WORST WEATHER IN THE COUNTRY TODAY IS...
The severe threat shifts back to the south and west, after over 600 damaging wind/large hail reports in the Mid-Atlantic yesterday. Parts of the Northern Plains and Florida are highlighted for the risk of damaging winds, large hail and a few isolated tornadoes. The better bet for twisters sits around Sioux Falls and Omaha. All told, I don't expect to see a similar number of severe weather reports compared to the last few days.
MONSOON SAFETY AWARENESS WEEK
The National Weather Service has designated this week as "Monsoon Safety Awareness Week". All week on Tucson Today & the blog, I've highlighted a different topic and tips to keep you safe and alive during Monsoon 2013. Click here for my earlier post on today's topic: beating the heat.
Monsoon Safety Awareness Week: Ways to beat the heat
June 9th - 14th has been designated as Monsoon Safety Awareness Week in Arizona. All week long, the blog will highlight different topics regarding how to stay safe and alive during Monsoon 2013. Today's topic: heat safety. Believe it or not, heat is the #1 weather-related killer in the United States. Be smart. Get that hike or bike ride in before 10 AM. Even if you aren't doing strenuous activity, stay hydrated. Finally, if you see a child or pet in a parked car, alert authorities immediately.
Here's more good advice from NWS Tucson...
A PERIOD OF EXTREME HEAT IS OFTEN ONGOING DURING THE ONSET OF THE MONSOON...AND EXTREME CAN ALSO OCCUR THROUGHOUT THE MONTHS OF JULY...AUGUST AND SEPTEMBER. EXCESSIVE HEAT IS BY FAR THE NUMBER ONE WEATHER-RELATED KILLER IN ARIZONA. RESIDENTS AND VISITORS TO ARIZONA OFTEN THINK THAT BECAUSE HUMIDITIES ARE LOW...THE DRY HEAT IS NOT A CAUSE FOR CONCERN. BECAUSE THE HEAT MAY NOT BE AS UNCOMFORTABLE AS IT IS IN MORE HUMID AREAS...PEOPLE DO NOT NOTICE ITS EFFECTS...SUCH AS DEHYDRATION...AS EASILY. WHEN OUT FOR A MORNING HIKE...ALWAYS TAKE ALONG EXTRA WATER IN THE EVENT YOU BECOME LOST OR INJURED. IT SOUNDS SIMPLE...BUT STAY OUT OF THE SUN IF POSSIBLE. TRY TO AVOID STRENUOUS ACTIVITY...ESPECIALLY DURING THE HOTTEST TIMES OF THE DAY. EVEN THOSE WHO WORK OUTDOORS AND PERCEIVE THEMSELVES AS USED TO THE HEAT SHOULD NOT MINIMIZE THE THREAT. WEAR LOOSE FITTING AND LIGHT COLORED CLOTHING...AND TAKE ADVANTAGE OF AIR CONDITIONING WHEN POSSIBLE. DRINK PLENTY OF WATER TO AVOID DEHYDRATION. AVOID CAFFEINATED AND ALCOHOLIC BEVERAGES WHICH CAN INCREASE STRESS ON THE BODY AND ACCELERATE DEHYDRATION. REMEMBER NEVER TO LEAVE A CHILD OR A PET IN A PARKED VEHICLE. TEMPERATURES CAN CLIMB TO MORE THAN 140 DEGREES IN JUST MINUTES. EACH YEAR ACROSS THE COUNTRY...TRAGIC INCIDENTS OCCUR IN WHICH CHILDREN DIE FROM EXCESSIVE HEAT AFTER BEING LEFT IN A PARKED VEHICLE. IN 2012...33 SUCH DEATHS OCCURRED. CHECK OFTEN ON ELDERLY FRIENDS...NEIGHBORS AND FAMILY. THE ELDERLY ARE GENERALLY MORE SUSCEPTIBLE TO HEAT-RELATED ILLNESS. IF YOU OR SOMEONE YOU ARE WITH BEGINS TO FEEL TIRED AND FLUSHED AND BEGIN TO SWEAT EXCESSIVELY...HEAT EXHAUSTION MAY BE SETTING IN. STOP ANY STRENUOUS ACTIVITIES IMMEDIATELY...DRINK MORE WATER...AND FIND A COOL PLACE TO REST. IF SOMEONE BECOMES DISORIENTED...STOPS SWEATING...HAS HOT DRY SKIN...OR EVEN WORSE...PASSES OUT...THAT PERSON IS PROBABLY EXPERIENCING HEAT STROKE...A SERIOUS MEDICAL CONDITION. CALL 911 IMMEDIATELY. IF POSSIBLE...MOVE THEM TO A COOLER LOCATION. FOR ADDITIONAL SAFETY INFORMATION GO TO WEATHER.GOV/TUCSON OR MONSOONSAFETY.ORG
Thursday’s Tucson Forecast: Sizzling stretch continues, dew points climbing
THE CLIFF NOTES
Today - Mostly sunny. 104°, west wind 10-15 MPH.
Tonight - Mostly clear skies. 76°, southeast wind 5 MPH.
Tomorrow - Mostly sunny, isolated shower or two near Intl/New Mexico borders. 102°, west wind 10-15 MPH.
Click here for my True View 4 video forecast
THE SHORT TERM
Yep, another triple digit day queued up for the Old Pueblo (day 13 in a row, to be exact). How about details on some signs of Monsoon life instead? Dew points (level of moisture in atmosphere) are up a good 15-20° compared to yesterday. We have a southeasterly flow aloft carrying in some Monsoon moisture. Not quite up to that coveted 54° point, but it's trending up. Could some rain follow suit?
THE LONG TERM
If you live in Douglas, Bisbee, Willcox & Hannagan Meadow, there is a slight chance of an isolated shower tomorrow and Saturday. Don't expect a soaking, just a few drops that leave those dust spots on your car. For the rest of southern Arizona, dry conditions prevail. High temps remain in the 102-105° range through the middle of next week.
THE WORST WEATHER IN THE COUNTRY TODAY IS...
The severe weather target today sits over the DC/Baltimore Beltway. Thunderstorms producing damaging winds & large hail are a good bet again, with a few tornadoes likely spinning up. Prime time for storms in the Mid-Atlantic should be late afternoon/early evening, affecting the daunting DC rush hour and first round of the US Open.
MONSOON SAFETY AWARENESS WEEK
The National Weather Service has designated this week as "Monsoon Safety Awareness Week". Through Friday on Tucson Today & the blog, I will be highlighting a different topic and tips to keep you safe and alive during Monsoon 2013. Click here for my earlier post on today's topic: dust storms.
Monsoon Safety Awareness Week: Dust storm facts
June 9th - 14th has been designated as Monsoon Safety Awareness Week in Arizona. Through Friday, the blog will highlight different topics regarding how to stay safe and alive during Monsoon 2013. Today's topic: dust storms. Interstate 10 north of Marana is a haboob hot spot, due to flat land and persistent drought. Frequently, severe thunderstorms produce dust storms in this area, making travel extremely dangerous during the Monsoon. Above are some driving tips if caught in a dust storm.
Here is more haboob information from NWS Tucson...
THUNDERSTORMS OFTEN PRODUCE WINDS IN ARIZONA WHICH CAUSE CONSIDERABLE PROPERTY DAMAGE AND WHICH AT TIMES CAN CREATE DUST STORMS. THESE STRONG WINDS ARE THE RESULT OF DOWNBURSTS...WHICH AS THEIR NAME IMPLIES...TRAVEL DOWNWARD FROM A THUNDERSTORM...HIT THE GROUND AND SPREAD OUT IN ALL DIRECTIONS. DOWNBURST WINDS CAN REACH SPEEDS OVER 100 MPH. THESE STRONG THUNDERSTORM WINDS CAN ALSO PRODUCE DUST STORMS OR HABOOBS...WHICH ARE SECOND ONLY TO FLASH FLOODS IN THE NUMBER OF THUNDERSTORM-RELATED DEATHS THEY PRODUCE IN ARIZONA. VISIBILITIES CAN BE REDUCED TO NEAR ZERO IN A MATTER OF SECONDS...CREATING TREACHEROUS CONDITIONS FOR MOTORISTS. IF YOU SEE A DUST STORM...DO NOT DRIVE INTO IT. PULL ASIDE AND STAY ALIVE! IF YOU FIND YOURSELF OVERTAKEN BY A DUST STORM...PULL AS FAR OFF THE ROAD AS YOU CAN IN A SAFE MATTER AS QUICKLY AS YOU CAN SO THAT YOU DO NOT STRIKE ANOTHER VEHICLE. AFTER PULLING OFF THE ROADWAY...IN ORDER TO DECREASE THE CHANCES OF OTHER MOTORISTS FOLLOWING YOUR TAIL LIGHTS AND STRIKING YOU FROM BEHIND...TURN OFF YOUR LIGHTS...PUT YOUR VEHICLE IN PARK...AND TAKE YOUR FOOT OFF THE BRAKE PEDAL. DUST STORMS USUALLY ONLY LAST A FEW MINUTES...SO KEEP YOUR SEAT BELT ON AND STAY WHERE YOU ARE UNTIL THE DUST STORM PASSES. FOR ADDITIONAL DUST STORM SAFETY INFORMATION GO TO PULLASIDESTAYALIVE.ORG AND VISIT WEATHER.GOV/TUCSON OR MONSOONSAFETY.ORG FOR ADDITIONAL SAFETY INFORMATION.
Wednesday’s Tucson Forecast: More heat, little Monsoon inroads next 7 days
THE CLIFF NOTES
Today - Mostly sunny & hot. 107°, west wind 10-15 MPH.
Tonight - Clear. 76°, south-southeast wind 5 MPH.
Tomorrow - Mostly sunny. 104°, west wind 10-15 MPH.
Click here for my True View 4 video forecast
THE SHORT TERM
Through the first 11 days of June, Tucson's average temperature is running 6° above normal. The June Fever doesn't look to break anytime soon. Heading for 107° at TIA this afternoon, with other metro locations a degree or two above/below that mark. The high cloud cover over us this morning should hang out again today. Temps drop a few degrees to wrap the work week as high pressure stays anchored over the Central Plains. That said, the triple digit stretch will continue.
THE LONG TERM
No significant changes to the forecast for the weekend into early next week. That high pressure center may begin to slide back toward Arizona Monday & Tuesday, which would serve to crank up the thermostat again. Lots of sunshine, little signs of the Monsoon arriving anytime soon. Stay patient, desert dwellers.
THE WORST WEATHER IN THE COUNTRY TODAY IS...
A stationary front should be the focal point for severe storms this afternoon & evening from the Chicagoland to western Ohio. There's a chance storms form into a line and track several hundred miles, known as a "derecho". If that's the case, the primary threat would be damaging winds and a few tornadoes. One limiting factor to a line of severe storms developing later on is morning cloud cover, which has been hanging tough around the Windy City. We'll track the developments today on News 4 Tucson at Noon.
PICTURE TIME!
What a lovely filtered sunset shot sent to us by viewer Brian Talley. He took this up in the Foothills during sunset on June 1st, when the ice officially broke in Tucson. Mother Nature paints quite the canvas, right? Thanks Brian for the photo!
MONSOON SAFETY AWARENESS WEEK
The National Weather Service has designated this week as "Monsoon Safety Awareness Week". Through Friday on Tucson Today & the blog, I will be highlighting a different topic and tips to keep you safe and alive during Monsoon 2013. Click here for my earlier post on today's topic: damaging microburst winds.
CURRENT TUCSON TEMP
CURRENT MT. LEMMON TEMP
