Thursday, June 12, 2014
There may be some storms later today, though with less coverage than yesterday, before a beautiful summer day is on tap for Friday. A wave currently over the Pacific northwest will affect our area for Saturday, though there is model disagreement with respect to the amount of cold air and moisture that is brought over our area. I would normally expect the weaker solutions this close to the summer solstice, but this may be similar to last Sunday when the wave came in far stronger and wetter than forecast.
As a result, while it is likely in either case that we will have some afternoon storms Saturday with cooler temperatures during the day, it is not clear as to whether early to midday Saturday will be cloudy with light precipitation developing relatively early in the day or partly sunny with storms holding off until the afternoon.
Cooler temperatures look to persist Sunday and into the following week as continued energy from the Pacific keep the summer ridge from building over our area. Model disagreement appears again early in the week with respect to the strength and speed of another storm moving in from the northwest.
In any case, seasonably cool temperatures will likely persist through at least midweek as it appears likely that some cool air will continue to filter into the region. After that, models indicate a building ridge that will bring much warmer temperatures into our region.
Thursday, June 5, 2014
Our pleasant summer weather should continue for the following week. Even though weak waves pass north of us almost every day for the next week, they will bring only slight cooling as they contain very little moisture. Their greatest impact will be along the Front Range where these weak cool frontal passages bring increased chances of severe weather.
Clouds may increase in the afternoon in the wake of these waves, with their greatest coverage and the greatest chance of light rain occurring Saturday and Sunday afternoons as the dry air over our region is eroded by the passing disturbances.
Model forecasts bring a stronger wave to the west coast by the following weekend, though there is great uncertainty as to the strength and path of this storm.
Thursday, May 29, 2014
The Category 4 hurricane southwest of the Baja peninsula that was Amanda became the strongest May eastern Pacific hurricane on record Sunday morning as peak winds approached that of a Category 5 hurricane. Much of the current moisture has been drawn northward from the remains of that hurricane, and will persist over our area through Saturday.
The moisture will keep the night unseasonably warm, and there will be enough daytime heating in spite of the cloud cover to force afternoon storms through Saturday. Additionally, weak and hard-to-time waves will enhance storms on Friday, leading to that day being the wettest of the period. The warm rain will accelerate the melting of the upper elevation snowpack leading to further rising of the rivers through the weekend.
Waves staying north of us, the first from the northwest late in the weekend and then a series from the southwest early in the week, will draw dry air into the region by Sunday, noticeably decreasing the chance of afternoon storms and lowering nighttime temperatures. The summery weather looks to last through most of next week before a weak wave may bring a threat of showers near the end of the workweek, though they would likely be limited to the typical afternoon variety.
Thursday, May 22, 2014
A large upper level low cut off from the mean westerly flow currently sits over central to southern California and will affect our weather for the Memorial Day weekend. Atmospheric moisture will increase each day in first southwest and then southerly flow as the low is forecast to lumber across Arizona and New Mexico through the long weekend. Additionally, a wave in the westerly flow to our north will interact with this low Saturday and more strongly Sunday bringing progressively stronger and wetter conditions to our region through Sunday night.
As is usual during the late spring and summer months, showers should increase as we approach the warmest part of the day, and then decrease as night falls, though the interaction with the wave to the north will keep activity going longer than normal Saturday and Sunday nights.
This interaction should move the low to our east by Monday and lead to noticeably drier and warmer weather. However we will still be susceptible to afternoon showers Monday as the cool air in the mid and upper levels left behind by the storm keeps the atmosphere unstable.
Conditions will be warmer and drier on Tuesday, though we may still see some passing afternoon showers. By early Wednesday, we are completely under the influence of a dry and summery warm airmass that looks to hang around through the remainder of the workweek.
Thursday, May 15, 2014
A couple of more days of unsettled early spring-like weather will be in store for tomorrow and and early Saturday as the huge storm that impacted us over the weekend finally trudges far enough east of us to allow the return of seasonable weather. Two shortwaves timed for Friday afternoon and Saturday morning will keep showers going, more so on Friday afternoon than Saturday.
By late Saturday or early Sunday, a rapidly building ridge will bring much warmer temperatures and drier air for the end of the weekend and extending into the beginning of the workweek. However, by midweek, another forecast storm approaching form the Pacific northwest splits, with models struggling with how much energy will be partitioned between the northern and southern branches.
Most models keep most of the storm to our southwest, with some of the storm moving quickly across the northern Rockies. Current forecasts skirt a cool front through our region sometime on Wednesday leading to an increased chance of showers. This will be followed later in the week with warm and possibly wet weather as the storm to our southwest moves over us late in the week or early in the Memorial Day weekend.